JP4175745B2 - Hot working support - Google Patents
Hot working support Download PDFInfo
- Publication number
- JP4175745B2 JP4175745B2 JP23569299A JP23569299A JP4175745B2 JP 4175745 B2 JP4175745 B2 JP 4175745B2 JP 23569299 A JP23569299 A JP 23569299A JP 23569299 A JP23569299 A JP 23569299A JP 4175745 B2 JP4175745 B2 JP 4175745B2
- Authority
- JP
- Japan
- Prior art keywords
- support
- support layer
- sic
- workpiece
- sintered body
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000463 material Substances 0.000 claims description 83
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 59
- 239000010410 layer Substances 0.000 claims description 57
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 38
- 238000000576 coating method Methods 0.000 claims description 34
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 34
- 239000011248 coating agent Substances 0.000 claims description 32
- 239000000758 substrate Substances 0.000 claims description 29
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 18
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 12
- 238000005507 spraying Methods 0.000 claims description 10
- 229910000423 chromium oxide Inorganic materials 0.000 claims description 9
- 229910052845 zircon Inorganic materials 0.000 claims description 9
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 claims description 9
- 229910052721 tungsten Inorganic materials 0.000 claims description 8
- 239000010937 tungsten Substances 0.000 claims description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 4
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 claims description 4
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 239000010703 silicon Substances 0.000 claims description 4
- 239000002356 single layer Substances 0.000 claims description 4
- 229910052596 spinel Inorganic materials 0.000 claims description 4
- 239000011029 spinel Substances 0.000 claims description 4
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 claims description 4
- 229910052726 zirconium Inorganic materials 0.000 claims description 3
- 230000000052 comparative effect Effects 0.000 description 27
- 238000010438 heat treatment Methods 0.000 description 23
- 239000002245 particle Substances 0.000 description 22
- 230000009257 reactivity Effects 0.000 description 16
- 238000000034 method Methods 0.000 description 15
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 11
- 238000002844 melting Methods 0.000 description 10
- 230000008018 melting Effects 0.000 description 10
- 239000000843 powder Substances 0.000 description 10
- 239000000919 ceramic Substances 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- 238000007751 thermal spraying Methods 0.000 description 9
- 239000012298 atmosphere Substances 0.000 description 8
- 230000006698 induction Effects 0.000 description 8
- 238000012545 processing Methods 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 7
- 230000003628 erosive effect Effects 0.000 description 7
- 239000010959 steel Substances 0.000 description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- 238000007750 plasma spraying Methods 0.000 description 6
- 238000005096 rolling process Methods 0.000 description 6
- 239000000377 silicon dioxide Substances 0.000 description 6
- YLZOPXRUQYQQID-UHFFFAOYSA-N 3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]propan-1-one Chemical compound N1N=NC=2CN(CCC=21)CCC(=O)N1CCN(CC1)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F YLZOPXRUQYQQID-UHFFFAOYSA-N 0.000 description 5
- 229910052782 aluminium Inorganic materials 0.000 description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- 150000002739 metals Chemical class 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 description 5
- HMUNWXXNJPVALC-UHFFFAOYSA-N 1-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperazin-1-yl]-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)N1CCN(CC1)C(CN1CC2=C(CC1)NN=N2)=O HMUNWXXNJPVALC-UHFFFAOYSA-N 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 4
- 229910052681 coesite Inorganic materials 0.000 description 4
- 229910052906 cristobalite Inorganic materials 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910002076 stabilized zirconia Inorganic materials 0.000 description 4
- 229910052682 stishovite Inorganic materials 0.000 description 4
- 229910052905 tridymite Inorganic materials 0.000 description 4
- VZSRBBMJRBPUNF-UHFFFAOYSA-N 2-(2,3-dihydro-1H-inden-2-ylamino)-N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]pyrimidine-5-carboxamide Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C(=O)NCCC(N1CC2=C(CC1)NN=N2)=O VZSRBBMJRBPUNF-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052581 Si3N4 Inorganic materials 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 3
- 238000005266 casting Methods 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000005242 forging Methods 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 239000010440 gypsum Substances 0.000 description 3
- 229910052602 gypsum Inorganic materials 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 2
- AFCARXCZXQIEQB-UHFFFAOYSA-N N-[3-oxo-3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CCNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 AFCARXCZXQIEQB-UHFFFAOYSA-N 0.000 description 2
- 229910003910 SiCl4 Inorganic materials 0.000 description 2
- 239000004115 Sodium Silicate Substances 0.000 description 2
- 239000000292 calcium oxide Substances 0.000 description 2
- 235000012255 calcium oxide Nutrition 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 239000011214 refractory ceramic Substances 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- GCLGEJMYGQKIIW-UHFFFAOYSA-H sodium hexametaphosphate Chemical compound [Na]OP1(=O)OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])OP(=O)(O[Na])O1 GCLGEJMYGQKIIW-UHFFFAOYSA-H 0.000 description 2
- 235000019982 sodium hexametaphosphate Nutrition 0.000 description 2
- 229910052911 sodium silicate Inorganic materials 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000001577 tetrasodium phosphonato phosphate Substances 0.000 description 2
- YIWGJFPJRAEKMK-UHFFFAOYSA-N 1-(2H-benzotriazol-5-yl)-3-methyl-8-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carbonyl]-1,3,8-triazaspiro[4.5]decane-2,4-dione Chemical compound CN1C(=O)N(c2ccc3n[nH]nc3c2)C2(CCN(CC2)C(=O)c2cnc(NCc3cccc(OC(F)(F)F)c3)nc2)C1=O YIWGJFPJRAEKMK-UHFFFAOYSA-N 0.000 description 1
- LDXJRKWFNNFDSA-UHFFFAOYSA-N 2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)-1-[4-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]piperazin-1-yl]ethanone Chemical compound C1CN(CC2=NNN=C21)CC(=O)N3CCN(CC3)C4=CN=C(N=C4)NCC5=CC(=CC=C5)OC(F)(F)F LDXJRKWFNNFDSA-UHFFFAOYSA-N 0.000 description 1
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 1
- JAWMENYCRQKKJY-UHFFFAOYSA-N [3-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-ylmethyl)-1-oxa-2,8-diazaspiro[4.5]dec-2-en-8-yl]-[2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidin-5-yl]methanone Chemical compound N1N=NC=2CN(CCC=21)CC1=NOC2(C1)CCN(CC2)C(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F JAWMENYCRQKKJY-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 208000037584 hereditary sensory and autonomic neuropathy Diseases 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 239000005355 lead glass Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 229910003465 moissanite Inorganic materials 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000004901 spalling Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000002230 thermal chemical vapour deposition Methods 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
Images
Landscapes
- Furnace Charging Or Discharging (AREA)
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
- Chemical Vapour Deposition (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、熱間加工用の被加工材を加熱・加工する際に、当該被加工材を支持するための熱間加工用支持体に関する。
【０００２】
【従来の技術】
熱間加工は、被加工材を加熱炉内で高温加熱した後、鍛造加工、圧延加工をはじめとする塑性加工を行う金属材料の加工方法であり、変形抵抗が低く、加工が容易であることから、自動車、建設機械、電機製品、農業機械等の各種金属部品の製造に広範に用いられている。
【０００３】
熱間加工においては、鍛造加工であれば断面が円形、正方形等に加工された鋼片であるビレット材等、圧延加工であれば平板状の鋼板等が被加工材として使用され、これらの被加工材を燃焼式加熱炉、誘導加熱炉等の加熱炉により所定の加工温度まで加熱した後、所望の形状に加工する。
例えば平板状の鋼板を圧延加工する場合には、所定の温度に加熱された鋼板を上下の圧延用ローラ間に挟持して圧延加工を行う。
【０００４】
また、円形断面のビレット材を誘導加熱炉で加熱し、鍛造加工する場合であれば、図２に示すように被加工材であるビレット材２０を、誘導加熱炉入口側からプッシャー、ピンチローラ等によってチューブ状に構成された炉心管１１内に連続的に送り込むことにより、炉心管１１内周の底面部を摺動させながら、各加熱ブロック１０の炉心管１１内を順番に通過させる。
【０００５】
この際、コイル導管１３への通電によって発生した誘導電流によってビレット材２０を順次加熱し、最後の加熱ブロック１０の炉心管１１に至るまでに所望の加工温度（例えば１２００℃）とし、次いで鍛造加工を行う。
【０００６】
上述の例においては、被加工材であるビレット材や鋼板を、誘導加熱炉の炉心管や圧延用ローラにより支持した状態で加熱・加工を行っている。即ち、当該炉心管や圧延用ローラは被加工材を加熱・加工する際の支持体として機能している（以下、このような部材を単に「支持体」という。）。
【０００７】
支持体には、少なくとも被加工材の加熱条件（温度、雰囲気等）における強度と高い熱伝導率が必要とされ、この他にも耐熱性、耐衝撃性、耐食性、低比熱であること等、種々の特性が要求される。従って、従来は耐火セラミックの中でもこれらの性質に優れる炭化珪素（以下、「ＳｉＣ」と記す。）、窒化珪素（以下、「Ｓｉ3Ｎ4」と記す。）、若しくは金属珪素含浸炭化珪素（以下、「Ｓｉ−ＳｉＣ」と記す。）からなる焼結体、が支持体として使用されてきた。
【０００８】
【発明が解決しようとする課題】
しかしながら、実際には支持体をＳｉＣ、Ｓｉ3Ｎ4、Ｓｉ−ＳｉＣからなる焼結体で構成した場合でも、被加工材との摩擦によって支持体が容易に溶損し、或いは極めて短期間で摩耗するため、支持体の耐用時間が１〜２ヶ月程度と短いという現象が生じていた。
【０００９】
この現象は、熱間加工が１２００℃程度という極めて高温で行われることに起因して、支持体を構成するＳｉＣ、Ｓｉ3Ｎ4、Ｓｉ−ＳｉＣと、被加工材中に加工性向上のため添加される低融点成分（例えば鉛等）、或いは被加工材自体（例えば鉄分等）とが反応してしまうためであると考えられる。
本発明は、このような従来技術の問題点に鑑みてなされたものであって、その目的とするところは、支持体としての要求特性を備えることに加え、溶損や摩耗が少なく耐用時間の長い熱間加工用支持体を提供することにある。
【００１０】
【課題を解決するための手段】
本発明者らが鋭意検討した結果、所定の気孔率のＳｉ−ＳｉＣの焼結体からなる基材の表面に、前記基材に比して被加工材との反応性が低い材質の溶射被膜からなる支持層を形成することにより、上記の従来技術の問題点を解決できることに想到して本発明を完成した。
【００１１】
即ち、本発明によれば、金属珪素含浸炭化珪素質の焼結体からなる基材と、当該基材の表面に形成された、被加工材を支持するための支持層と、から構成された熱間加工用の支持体であって、前記基材が気孔率２〜８％の金属珪素含浸炭化珪素質の焼結体からなり、前記支持層が、前記基材に比して被加工材との反応性が低い材質の溶射被膜からなることを特徴とする熱間加工用支持体が提供される。
【００１２】
本発明の支持体は、支持層がタングステン、ジルコニウム、タングステンカーバイド、ジルコニア、ジルコン、スピネル、酸化クロム、アルミナ−ジルコニア混合物、アルミナ−酸化クロム混合物のうちの少なくとも１種からなることが好ましく、基材形状がチューブ状、樋状又はローラ状である場合に好適に用いることができる。
【００１３】
また、本発明の支持体は、支持層が単層若しくは複層の被膜状であることが好ましく、支持層がタングステン、ジルコニア又はジルコンの溶射被膜からなることが更に好ましい。
【００１５】
【発明の実施の形態】
本発明の熱間加工用支持体（以下、単に「支持体」という。）は、所定の気孔率のＳｉ−ＳｉＣ焼結体からなる基材の表面に、前記基材に比して被加工材との反応性が低い材質の溶射被膜からなる支持層を有することを特徴とする。
【００１６】
このような支持体は、支持体としての要求特性に優れるＳｉ−ＳｉＣによって基材が構成されることに加え、被加工材は専ら支持層によって支持される。即ち、被加工材と基材を構成するＳｉ−ＳｉＣとは直接接触せず、両者は反応しないため、支持体の溶損や摩耗が少なく耐用時間を長くすることが可能である。
以下、本発明について詳細に説明する。
【００１７】
（１）基材
基材は支持体の主たる構成部分であるため、少なくとも被加工材の加熱条件（温度、雰囲気等）における強度と高い熱伝導率を有する材質で構成することが必要であり、この他にも耐熱性、耐衝撃性、及び耐食性を備えた材質で構成することが好ましく、均一かつ速やかな加熱を担保するべく比熱が小さい材質により構成することが好ましい。
【００１８】
例えば、耐火セラミックの中でも特に上記特性に優れる炭化珪素質（以下、「ＳｉＣ質」と記す。）、窒化珪素質（以下、「Ｓｉ３Ｎ４質」と記す。）、若しくは金属珪素含浸炭化珪素質（以下、「Ｓｉ−ＳｉＣ質」と記す。）からなる焼結体を挙げることができる。
なお、本発明の支持体は基材表面に支持層を形成するため、基材については耐摩耗性や被加工材との反応性を考慮する必要はない。
【００１９】
ＳｉＣ質焼結体としては、例えばＳｉＯ2結合のＳｉＣ焼結体やＳｉ3Ｎ4結合のＳｉＣ焼結体等が、Ｓｉ3Ｎ4質焼結体としては、例えばＳｉ3Ｎ4原料粉末に、イットリア等の焼結助剤を添加混合して成形後、焼成して得られるＳｉ3Ｎ4焼結体等が挙げられる。
【００２０】
上記いずれの焼結体もＳｉＣ、Ｓｉ3Ｎ4のみで構成されている必要はなく、ＳｉＣ、Ｓｉ3Ｎ4を主成分とするもの、具体的にはＳｉＣ、Ｓｉ3Ｎ4が７５重量％以上焼結体中に含まれているものであれば足りる。
なお、基材としてより高い熱伝導性が要求される場合にはＳｉＣ質焼結体を、耐衝撃性が要求される場合にはＳｉ3Ｎ4質焼結体を選択することが好ましい。
【００２１】
但し、本発明においては支持体の基材をＳｉ−ＳｉＣ質焼結体により構成することとした。Ｓｉ−ＳｉＣ質焼結体は熱伝導性、強度に優れるため、本発明の支持体を構成する基材として特に好適に用いることができるからである。
Ｓｉ−ＳｉＣ質焼結体とは、金属Ｓｉ及びＳｉＣを構成成分として含む焼結体をいい、例えば本出願人が既に開示した、ＳｉＣ粉体、黒鉛粉、有機質バインダー及び、水分又は有機溶剤を含有してなる成形用原料を成形し、当該成形体を金属Ｓｉ雰囲気で、かつ減圧の不活性ガス雰囲気又は真空中において、１３５０〜２５００℃で焼成してなるＳｉ−ＳｉＣ質焼結体等が挙げられる（特開平５−２７０９１７号公報）。
【００２２】
Ｓｉ−ＳｉＣ質焼結体を基材として選択する場合には、焼結体中の金属Ｓｉ含有量を２〜３５重量％とすると、支持体の耐衝撃性、均熱性、耐食性が向上するため好ましい。金属Ｓｉが２重量％未満では耐食性、耐衝撃性が低下する場合があり、３５重量％超では均熱性の面で劣る場合がある。
なお、金属Ｓｉ含有量は金属Ｓｉ、黒鉛粉、増孔剤の添加量により制御することが可能である。
【００２３】
基材の形状は、加熱炉の方式等によって適宜選択することができる。例えば誘導加熱炉を使用する場合であれば基材に誘導電流を流さないため樋状（半割チューブ状）であることが好ましく、燃焼式加熱炉を使用する場合にはチューブ状とする必要がある。
また、鋼板を圧延加工する場合であればローラ状のものを使用すればよい。
【００２４】
（２）支持層
本発明の支持体は、基材の表面に支持層を形成している。このような構成により、被加工材は専ら支持層によって支持され、基材を構成するＳｉＣ等とは直接接触しないため、被加工材中の成分（例えば鉛等）や被加工材自体（例えば鉄等）との反応による基材（即ち支持体）の溶損や摩耗を防止することができる。
【００２５】
支持層は、少なくとも基材と比較して被加工材との反応性が低い材質からなることが要求される。本明細書において「被加工材との反応性」というときは、被加工材の加熱・加工条件（温度、雰囲気等）における被加工材との反応性を意味し、被加工材自体との反応性の他、被加工材中の成分（例えば鉛等の低融点成分）との反応性も含まれる。具体的には被加工材自体或いは被加工材中の成分と反応して低融点成分を形成するような材質では支持層が損耗してしまうため好ましくない。例えばシリカは被加工材中の鉛と反応して低融点の鉛ガラスを生成するため、アルミナや金属珪素も鉄（即ち被加工材自体）と反応して低融点成分を生成するため支持層を構成する材質としては不適である。
【００２６】
「被加工材との反応性が低い材質」は、被加工材の成分組成や加熱・加工条件等により異なるため、条件に適合する材質を個別に選択する必要がある。但し、低融点成分の鉛を０．５重量％程度含む一般的なビレット材、鋼板を１２００℃程度で加工する場合（以下、このような条件を「一般的な加工条件」という。）を想定すれば、被加工材との反応性が低い金属としてはタングステン、ジルコニウム等が、セラミックとしては、タングステンカーバイド、ジルコニア、ジルコン、スピネル、酸化クロム（Ｃｒ2Ｏ3）等が挙げられる。
【００２７】
更には、アルミナ−ジルコニア混合物、アルミナ−酸化クロム混合物等のように２種以上のセラミック又は金属の混合物であっても良い。一般的な加工条件の下では、アルミナ−ジルコニア混合物であればジルコニアが少なくとも１０重量％以上含まれていることが必要であり、アルミナ−酸化クロム混合物であれば酸化クロムが少なくとも５％以上含まれていることが必要である。
【００２８】
なお、被加工材との反応性については、実際の加熱・加工条件（温度、雰囲気等）の下でテストピース上に被加工材を一定時間載置し、テストピース表面の変質の程度を確認する方法により比較的簡便に評価できる。
【００２９】
支持層は被加工材と基材とを接触させないため、ある程度の厚みを有していることが必要である。このような観点から支持層の厚みは少なくとも０．２ｍｍ超であることが必要であり、０．５ｍｍ以上であることが好ましく、１ｍｍ以上であることが更に好ましい。被加工材と基材が接触しないことを条件としてその形態は特に限定されないが、例えば単層若しくは複層の被膜状とする方法や、基材表面に複数の板状体を配置して支持層とする方法等が挙げられる。上記いずれの形態であっても、被加工材は専ら支持層によって支持され、基材表面と接触することはないため本発明の目的を達成することができる。
【００３０】
支持層を被膜状とする場合には、例えば溶射、ＣＶＤ、スパッタ、真空蒸着、スクリーン印刷、セラミックスラリーをディッピング後焼成する等、従来公知の膜形成法により支持層を形成できる。
被膜は単層のものは勿論のこと、複層のものであってもよく、例えば図１に示すようにチューブ状、樋状の基材２の内周面に被膜３を形成すればよい。
【００３１】
但し、本発明においては支持体の支持層を溶射により形成された溶射被膜とした。溶射によれば厚み０．５ｍｍ程度の被膜を形成することも可能であり、また、溶射被膜は３０００〜６０００℃の高温で溶融した金属やセラミックを基材に噴射して形成するため被膜の強度が高いからである。
【００３２】
溶射被膜の材質としては、既述した金属、セラミック、或いは２種以上のセラミック又は金属の混合物を好適に用いることができるが、特にタングステン、ジルコニア、又はジルコンからなる溶射被膜とすることが被加工材との反応性が低い点において好ましい。中でもジルコン（ＺｒＳｉＯ4）は耐摩耗性、耐食性にも優れ、溶融金属に濡れ難いという特徴をも有するため溶射被膜を構成する材質として好適に用いることができる。
溶射方法は特に限定されないが、タングステンのような高融点材料の溶射が可能であるプラズマ溶射が好ましい。
【００３３】
本発明においては支持層を溶射被膜とするため、気孔率が２〜８％のＳｉ−ＳｉＣ焼結体からなる基材に溶射被膜を形成する。
基材の気孔率が２％未満であると溶射被膜が基材に強固に固着しない一方、気孔率が８％を超えるとＳｉ−ＳｉＣの特徴である熱伝導性が低下し、加熱開始時や温度差がつきやすい部分において支持体がスポーリングにより破損したり、局部的なオーバーヒート状態を生じた場合に支持体表面に劣化を生じる場合があるからである。
【００３４】
Ｓｉ−ＳｉＣからなる基材の表面にＳｉＣのＣＶＤ被膜からなる支持層を有する支持体も好ましい。ＣＶＤによれば厚み１ｍｍ程度の被膜を形成することが可能であり、また、ＣＶＤ被膜は化学反応を利用して膜を形成するため被膜が緻密であり、耐摩耗性に優れ、被加工材との反応性も低いからである。Ｓｉ−ＳｉＣからなる基材にＳｉＣのＣＶＤ被膜を形成すると、熱伝導性に優れ、被加工材との反応性が低い支持体を構成できる点において特に好ましい。
【００３５】
支持層を複数の板状体を基材表面に配置して形成する場合には、既述した金属、セラミック、或いは２種以上のセラミック又は金属の混合物からなる板状体を基材の表面、即ち被加工材との接触面に配置すればよい。
複数の板状体を基材表面に配置して支持層を形成する方法は、機械的なはめ込みや接着が可能であり、溶射やＣＶＤと比較して支持層の厚みを大きくできる点において好ましい。
【００３６】
例えば、被加工材との反応性が低いセラミックであるジルコニア焼結体をチューブ状や樋状の基材の内周面、或いはローラ状基材の表面に貼着することにより支持層を形成することができる。
セラミック焼結体を基材表面に貼着する方法としては、例えばアルミナ−シリカ−珪酸ソーダ、アルミナ−シリカ−ＳｉＣ−燐酸アルミニウム等の無機質接着剤により接着する方法等が挙げられる。
【００３７】
支持層は、必ずしも基材表面の全面を被覆するように形成する必要はなく、基材表面に断続的に形成してもよい。例えば図３，図４に示すように基材表面に帯状若しくは斑点状に形成することも可能である。
このような方法は、支持層と基材との熱膨張率の差を緩和できるので、支持層の剥離を防止することができる点において好ましい。
帯状若しくは斑点状の支持層は、例えば支持層と相補的な形状にスリット、孔を設けたアルミ板等で基材表面をマスキングして溶射を行う方法、基材表面に帯状若しくは斑点状に板状体を配置する方法等によって形成することができる。
【００３８】
【実施例】
以下、本発明の支持体について、実施例により更に詳細に説明する。但し、本発明はこれらの実施例に限定されるものではない。
【００３９】
（参考例１）
参考例１では、以下に示すＳｉＯ２結合ＳｉＣ、Ｓｉ３Ｎ４又はＳｉ−ＳｉＣの焼結体を長さ５０ｍｍ×幅５０ｍｍ×厚さ８ｍｍの形状としたものを基材とし、当該基材の表面に種々の材質で支持層を形成し、被加工材との反応性を評価した。
【００４０】
▲１▼ＳｉＯ2結合ＳｉＣ：平均粒径２５０μｍ（最大粒径５００μｍ）の骨材となるＳｉＣを６５重量％、平均粒径８μｍ（最大粒径２０μｍ）の微粉のＳｉＣを３５重量％からなる混合物１００％に対し、結合材生成用助剤としてＣａＯ，Ｖ2Ｏ5を各々０．５重量％、バインダとしてヘキサメタリン酸ナトリウムを０．５重量％、水を２０重量％添加し混合した後、セッコウ型を用いた鋳込み成形により成形体を得た。
【００４１】
当該成形体は８０℃で１０時間乾燥後、酸化雰囲気で、１４００℃で５時間焼成して焼結体を得た（以下、「焼結体Ａ」という。）。焼結体の組成はＳｉＣ：ＳｉＯ2：その他の成分＝８７：１２：１であり、見かけ気孔率が８．５％、嵩比重が２．５６であった。
【００４２】
▲２▼Ｓｉ3Ｎ4：平均粒径１０μｍのＳｉ3Ｎ4９５重量％、焼結助剤のＹ2Ｏ3５重量％からなる混合物１００重量％に対し、３０重量％の水を添加し混合した後、セッコウ型を用いた鋳込み成形を行い、更にＣＩＰ処理を施すことにより成形体を得た。当該成形体は、窒素雰囲気下、１９００℃で焼成して焼結体を得た（以下、「焼結体Ｂ」という。）。
【００４３】
▲３▼Ｓｉ−ＳｉＣ：平均粒径８０μｍ（最大粒径２００μｍ）の骨材となるＳｉＣを６５重量％、平均粒径５μｍ（最大粒径８μｍ）の微粉のＳｉＣを３０重量％、カーボン粉末５重量％からなる混合物１００％に対し、バインダとしてヘキサメタリン酸ナトリウムを０．５重量％、水を２５重量％添加し混合した後、セッコウ型を用いた鋳込み成形により成形体を得た。
【００４４】
当該成形体は８０℃で１０時間乾燥後、金属Ｓｉ雰囲気で、かつ、真空中において、１６５０℃で金属Ｓｉを含浸させながら焼成して焼結体を得た（以下、「焼結体Ｃ」という。）。焼結体の組成はＳｉＣ：Ｓｉ＝８１：１９であり、見かけ気孔率が０．２％、嵩比重が２．９９であった。
【００４５】
（比較例１−１〜１−３）
比較例１−１は焼結体Ａ、比較例１−２は焼結体Ｂ、比較例１−３は焼結体Ｃを所定形状（長さ５０ｍｍ×幅５０ｍｍ×厚さ８ｍｍ）とし、そのまま使用した。
【００４６】
（参考例１−１）
比較例１−３のサンプルに粒径５０〜１００μｍのタングステン粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。
【００４７】
（参考例１−２）
比較例１−３のサンプルに粒径１０〜７４μｍの金属ジルコニウム粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。
【００４８】
（参考例１−３）
比較例１−３のサンプルに粒径２０〜８８μｍのタングステンカーバイド粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。
【００４９】
（参考例１−４）
比較例１−３のサンプルに粒径３０〜７０μｍの安定化ジルコニア（ジルコニア：イットリア重量比＝９２：８）粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。
【００５０】
（参考例１−５）
比較例１−３のサンプルに粒径１０〜７４μｍのジルコン（ジルコニア：シリカ重量比＝６５：３５）粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。
【００５１】
（参考例１−６）
比較例１−３のサンプルに粒径５０〜１００μｍのスピネル（アルミナ：マグネシア重量比＝６５：３５）粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。
【００５２】
（参考例１−７）
比較例１−３のサンプルに粒径４４〜１０５μｍのアルミナ−酸化クロム（重量比９３：７）の混合粉末をプラズマ溶射して膜厚５００μｍの溶射被膜を形成した。即ち、混合物の溶射被膜を形成した。
【００５３】
（参考例１−８）
比較例１−３のサンプルに粒径５０〜１００μｍのタングステン粉末をプラズマ溶射して膜厚５０μｍの溶射被膜を形成し、更に粒径３０〜７０μｍのアルミナ：ジルコニア（重量比８０：２０）の混合粉末をプラズマ溶射して膜厚３００μｍの溶射被膜を形成した。即ち、複層の溶射被膜を形成した。
【００５４】
（参考例１−９）
比較例１−３のサンプルに対し、ＳｉＣ生成用ガスであるＣＨ４とＳｉＣｌ４との混合ガスを１３００℃で反応させてＣＶＤ処理を行い、膜厚５００μｍのＳｉＣのＣＶＤ被膜を形成した。
【００５５】
（評価）
参考例、比較例のサンプルの表面に０．５重量％の鉛を含有する、長さ１０ｍｍ×幅１０ｍｍ×厚さ１０ｍｍのビレット材を載置し、表１に記載の温度条件の下８時間保持し、サンプル表面の溶損の程度を目視判断することにより、ビレット材との反応性を評価した。溶損の程度は溶損が全く認められないか、極わずかに溶損が認められるものを◎、部分的に溶損が認められるものを○、全体的に溶損が認められるものを×として評価した。その結果を表１に示す。
【００５６】
【表１】
表１に示したように、通常の熱間加工の加熱温度１２００℃においては支持層を形成していない比較例１−１〜１−３のサンプルは溶損が認められたのに対し、支持層を形成した参考例１−１〜１−９のサンプルには溶損が認められなかった。参考例１−１（タングステン溶射），１−４（ジルコニア溶射），１−５（ジルコン溶射）は１３２０℃という高温条件でも溶損は認められず参考例のサンプルの中でも特に良好な結果を示した。
【００５８】
（参考例２）
参考例２では、支持体の表面で被加工材を実際に往復運動させて支持体の溶損、摩耗の程度を評価した。支持体としては、参考例１と同様の方法で作製した長さ２５０ｍｍ×幅１００ｍｍ×厚さ８ｍｍの板状焼結体を基材とし、当該基材の表面に断続的に支持層を形成したものを使用した。
【００５９】
（比較例２−１，２−２）
比較例２−１は焼結体Ａ、比較例２−２は焼結体Ｃを所定形状（長さ２５０ｍｍ×幅１００ｍｍ×厚さ８ｍｍ）とし、そのまま使用した。
【００６０】
（参考例２−１）
幅５ｍｍのスリットが１０ｍｍ間隔で設けられているアルミニウム製のスリット板で比較例２−２のサンプルをマスキングし、粒径５０〜１００μｍのタングステン粉末をプラズマ溶射して、図３に示すように幅５ｍｍ、膜厚５００μｍの帯状の溶射被膜３３を１０ｍｍ間隔で形成した。
【００６１】
（参考例２−２）
隣接する３つの孔の中心を結んだときに各辺１２ｍｍの正三角形となるように１０ｍｍφの孔が穿設された、アルミニウム製の有孔板で比較例２−２のサンプルをマスキングし、粒径５０〜１００μｍのタングステン粉末をプラズマ溶射して、図４に示すように１０ｍｍφ、膜厚５００μｍの溶射被膜４３を斑点状に形成した。
【００６２】
（参考例２−３）
図５に示すように比較例２−２のサンプルに、長さ１０ｍｍ×幅１０ｍｍ×厚さ１ｍｍの形状とした、見掛け気孔率０％、見かけ比重６．０の安定化ジルコニア（ジルコニア：イットリア重量比＝９２：８）焼結体５３を２ｍｍ間隔で、アルミナ−シリカ−珪酸ソーダ無機質接着剤を使用して貼着した。
【００６３】
（評価）
参考例、比較例のサンプルの表面に０．５重量％の鉛を含有する、長さ５０ｍｍ×幅１００ｍｍ×厚さ２０ｍｍの板状ビレット材を載置し、Ｏ２：Ｎ２重量比が５：９５の雰囲気の電気炉中で１３００℃に加熱し、速度２０ｍｍ／秒で１００時間往復運動させ、サンプル表面の損耗度を評価した。支持体の表面の損耗が厚さ０．１ｍｍ以下であれば◎、０．１〜１ｍｍであれば○、１ｍｍ超であれば×として評価した。その結果を表２に示す。
なお、ビレット材は酸化による組織変化の影響を避けるため、５時間おきに交換しながら評価を行った。
【００６４】
【表２】
その結果、表２に示すように比較例２−１，２−２では厚さ１ｍｍを超える損耗が認められたのに対し、参考例２−１，２−２の損耗は厚さ０．１ｍｍ以下と殆ど認められず良好な結果を示した。参考例２−３はやや損耗が認められるものの十分実用可能なレベルであり、実機における耐用時間は比較例２−１（１〜２ヶ月程度）の２倍以上とすることが期待できる。
【００６６】
（実施例３）
実施例３では、支持体の表面で被加工材を実際に往復運動させて支持体の溶損、摩耗の程度を評価した。支持体は、参考例１と同様の方法で作製した長さ２００ｍｍ×内径６８ｍｍφ×外径８０ｍｍφの中空管を半割した樋状のＳｉ−ＳｉＣ焼結体を基材とし（以下、「焼結体Ｄ」という。）、当該基材の表面に支持層を形成したものを使用した。但し、基材は鋳込み成形ではなく、押出成形で作製した。焼結体ＤのＳｉＣ：Ｓｉ重量比は８０：２０、焼結体の見掛け気孔率は２．５％であった。
【００６７】
（比較例３−１）
焼結体Ｄに支持層を形成せずそのまま使用した。
【００６８】
（実施例３−１）
焼結体Ｄに粒径３０〜７０μｍの安定化ジルコニア（ジルコニア：イットリア重量比＝９２：８）粉末をプラズマ溶射して、図６（ａ）に示すように膜厚５００μｍの溶射被膜６３を形成した。
【００６９】
（実施例３−２）
幅５ｍｍのスリットが２ｍｍ間隔で設けられているアルミニウム製のスリット板で焼結体Ｄをマスキングし、粒径３０〜７０μｍのジルコニア（ジルコニア：カルシア重量比＝９６：４）粉末をプラズマ溶射して、図６（ｂ）に示すように幅５ｍｍ、膜厚５００μｍの帯状の溶射被膜７３を２ｍｍ間隔で形成した。
【００７０】
（実施例３−３）
隣接する３つの孔の中心を結んだときに各辺１２ｍｍの正三角形となるように１０ｍｍφの孔が穿設された、アルミニウム製の有孔板で焼結体Ｄをマスキングし、実施例１−１と同様の方法で溶射を行い、図６（ｃ）に示すように１０ｍｍφ、膜厚５００μｍの溶射被膜８３を斑点状に形成した。
【００７１】
（参考例３−１）
焼結体Ｄに対し、ＳｉＣ生成用ガスであるＣＨ４とＳｉＣｌ４との混合ガスを１３００℃で反応させてＣＶＤ処理を行い、図６（ａ）に示すように膜厚５００μｍのＳｉＣのＣＶＤ被膜を形成した。
【００７２】
（評価）
実施例、参考例、比較例のサンプルの表面に０．５重量％の鉛を含有する、長さ１００ｍｍ×外径５５ｍｍφの円柱状ビレット材を使用し、参考例２と同様にしてサンプル表面の損耗量を評価した。支持体の表面の損耗が厚さ０．１ｍｍ以下であれば◎、０．１〜１．０ｍｍであれば○、１．０ｍｍ超であれば×として評価した。その結果を表３に示す。
なお、ビレット材は酸化による組織変化の影響を避けるため５時間おきに交換しながら評価を行った。
【００７３】
【表３】
その結果、表３に示すように比較例３−１の支持体は厚さ２．５ｍｍを超える損耗が認められたのに対し、実施例３−１〜３−３、参考例３−１の支持体は損耗が厚さ０．５ｍｍ以下と殆ど認められず良好な結果を示した。
【００７５】
（実施例４）
実施例４では、Ｓｉ−ＳｉＣ焼結体の気孔率が、支持体の熱伝導率及び溶射被膜の固着強度に与える影響について評価した。実施例４でも、参考例１と同様の方法で作製したＳｉ−ＳｉＣ焼結体を長さ５０ｍｍ×幅５０ｍｍ×厚さ８ｍｍに切断したものを基材とした。但し、焼成の際に金属Ｓｉの含浸量を調整することにより、０．３〜１０％の範囲内で見かけ気孔率が異なる７水準の基材を作製し、実施例３−１と同様に各基材に粒径３０〜７０μｍの安定化ジルコニア（ジルコニア：イットリア重量比＝９２：８）粉末をプラズマ溶射して、膜厚５００μｍの溶射被膜を形成した。
【００７６】
基材と溶射被膜の固着強度は、図７に示すように各支持体９１の基材９２側及び支持層９３側の双方にエポキシ樹脂系接着剤により測定用治具９４の平板部（２０ｍｍ×２０ｍｍ）を接着し、引張強度を測定することにより評価した。熱伝導率は JIS R2618に準拠し熱線法にて測定した。
その結果を表４に示す。
【００７７】
【表４】
表４に示すようにＳｉ−ＳｉＣ焼結体の見かけ気孔率が本発明の範囲（２〜８％）のものについては熱伝導率、溶射被膜の固着強度とも良好であった。一方、見掛け気孔率が２％未満のものは溶射被膜が強固に固着されず、８％超のものは熱伝導率が低下した。
【００７９】
【発明の効果】
以上説明したように、本発明の支持体は、所定の気孔率のＳｉ−ＳｉＣ焼結体からなる基材の表面に、前記基材と比較して、被加工材との反応性が低い材質の溶射被膜からなる支持層を形成したので、支持体として必要な耐熱性、強度、耐衝撃性、耐食性、耐摩耗性、低比熱、高熱伝導率を備えるとともに、支持体の溶損や摩耗を防止できる。
従って、例えば燃焼式加熱炉や誘導加熱炉の炉心管、圧延用ローラとして好適に用いることができる。
【図面の簡単な説明】
【図１】 本発明の熱間加工用支持体の一の実施例を示す概略斜視図（ａ），（ｂ）である。
【図２】 誘導加熱炉の形態を示す縦断面図である。
【図３】 本発明の熱間加工用支持体の実施態様を示す概略斜視図である。
【図４】 本発明の熱間加工用支持体の実施態様を示す概略斜視図である。
【図５】 本発明の熱間加工用支持体の実施態様を示す概略斜視図である。
【図６】 本発明の熱間加工用支持体の実施態様を示す概略斜視図（ａ），（ｂ），（ｃ）である。
【図７】 支持層の固着強度の試験方法を示す概略説明図であって、（ａ）は側面図、（ｂ）は斜視図である。
【符号の説明】
１…熱間加工用支持体、２…基材、３…支持層、４…被加工材（ビレット材）、１０…加熱ブロック、１１…炉心管、１１ｃ…フランジ部、１２…断熱材、１３…コイル導管、１４…外殻、２０…ビレット材、３１…熱間加工用支持体、３２…基材、３３…支持層、４１…熱間加工用支持体、４２…基材、４３…支持層、５１…熱間加工用支持体、５２…基材、５３…支持層、６１…熱間加工用支持体、６２…基材、６３…支持層、７１…熱間加工用支持体、７２…基材、７３…支持層、８１…熱間加工用支持体、８２…基材、８３…支持層、９１…熱間加工用支持体、９２…基材、９３…支持層、９４…治具。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hot working support for supporting a workpiece when the workpiece for hot working is heated and processed.
[0002]
[Prior art]
Hot working is a processing method for metal materials in which a workpiece is heated at a high temperature in a heating furnace and then subjected to plastic working including forging and rolling, and has low deformation resistance and is easy to work. And widely used in the manufacture of various metal parts such as automobiles, construction machinery, electrical products, and agricultural machinery.
[0003]
In hot working, billet materials, which are steel slabs processed into a circular or square shape in the case of forging, and flat steel plates in the case of rolling, are used as work materials. The workpiece is heated to a predetermined processing temperature in a heating furnace such as a combustion heating furnace or an induction heating furnace, and then processed into a desired shape.
For example, when a flat steel plate is rolled, the steel plate heated to a predetermined temperature is sandwiched between upper and lower rolling rollers and rolled.
[0004]
In addition, when the billet material having a circular cross section is heated in an induction heating furnace and forged, the
[0005]
At this time, the
[0006]
In the above-described example, the billet material or the steel plate, which is the workpiece, is heated and processed while being supported by the core tube of the induction heating furnace or the rolling roller. That is, the furnace core tube and the rolling roller function as a support for heating and processing the workpiece (hereinafter, such a member is simply referred to as “support”).
[0007]
The support must have at least strength and high thermal conductivity under the heating conditions (temperature, atmosphere, etc.) of the workpiece, and in addition to this, it must have heat resistance, impact resistance, corrosion resistance, low specific heat, etc. Various characteristics are required. Accordingly, silicon carbide (hereinafter referred to as “SiC”) and silicon nitride (hereinafter referred to as “Si”), which are excellent in these properties among refractory ceramics.ThreeNFour". ), Or a sintered body made of metal silicon-impregnated silicon carbide (hereinafter referred to as “Si—SiC”) has been used as a support.
[0008]
[Problems to be solved by the invention]
However, actually, the support is made of SiC, SiThreeNFourEven when it is composed of a sintered body made of Si—SiC, the support easily melts down due to friction with the work material or wears in a very short period of time, so the service life of the support is about 1 to 2 months. The phenomenon of short was occurring.
[0009]
This phenomenon is caused by the fact that hot working is performed at an extremely high temperature of about 1200 ° C.ThreeNFourIt is thought that this is because Si-SiC reacts with a low melting point component (for example, lead or the like) added to improve the workability in the workpiece, or the workpiece itself (for example, iron). .
The present invention has been made in view of such problems of the prior art, and the object of the present invention is to provide the required characteristics as a support, in addition to less melting and wear, and to shorten the service life. It is to provide a long hot working support.
[0010]
[Means for Solving the Problems]
As a result of intensive studies by the inventors,For a given porosityA material having a low reactivity with the workpiece compared to the base material on the surface of the base material made of a sintered body of Si-SiCSprayed coatingThe present invention was completed by conceiving that the problems of the prior art can be solved by forming a support layer comprising
[0011]
That is, according to the present invention,Metallic silicon impregnated silicon carbideA support for hot working, comprising: a base material made of a sintered body; and a support layer formed on the surface of the base material for supporting a workpiece,The substrate is made of a metal silicon impregnated silicon carbide sintered body having a porosity of 2 to 8%,Material in which the support layer is less reactive with the workpiece than the base materialSprayed coatingA support for hot working is provided.
[0012]
In the support of the present invention, the support layer is preferably composed of at least one of tungsten, zirconium, tungsten carbide, zirconia, zircon, spinel, chromium oxide, an alumina-zirconia mixture, and an alumina-chromium oxide mixture. It can be suitably used when the shape is a tube shape, a bowl shape or a roller shape.
[0013]
In the support of the present invention, the support layer is preferably a single layer or a multi-layer coating, and the support layer is more preferably composed of a thermal spray coating of tungsten, zirconia or zircon..
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The support for hot working of the present invention (hereinafter simply referred to as “support”)Si-SiC with a predetermined porosityA material having a low reactivity with the workpiece compared to the base material on the surface of the base material made of a sintered bodySprayed coatingIt has the support layer which consists of.
[0016]
Such a support is excellent in required properties as a support.Si-SiCIn addition to the construction of the substrate, the workpiece is supported exclusively by the support layer. That is, it constitutes the workpiece and the base materialSi-SiCIs not in direct contact with each other and does not react with each other, so that the support is less likely to be melted or worn and the service life can be extended.
Hereinafter, the present invention will be described in detail.
[0017]
(1) Base material
Since the base material is the main component of the support, it must be made of a material that has at least strength and high thermal conductivity under the heating conditions (temperature, atmosphere, etc.) of the workpiece. It is preferable to use a material having a low specific heat so as to ensure uniform and rapid heating.
[0018]
For example,Among refractory ceramics, silicon carbide (hereinafter referred to as “SiC quality”) and silicon nitride (hereinafter referred to as “SiC”), which are particularly excellent in the above characteristics.3N4"Quality". ) Or a sintered body made of metal silicon-impregnated silicon carbide (hereinafter referred to as “Si—SiC”).Can mention.
In addition, since the support body of this invention forms a support layer in the base-material surface, it is not necessary to consider abrasion resistance and the reactivity with a to-be-processed material about a base material.
[0019]
As the SiC sintered body, for example, SiO2Bonded SiC sintered body or SiThreeNFourBonded SiC sintered body is SiThreeNFourAs the sintered material, for example, SiThreeNFourSi obtained by sintering after adding and mixing a sintering aid such as yttria to the raw material powderThreeNFourA sintered body etc. are mentioned.
[0020]
Any of the above sintered bodies is SiC, SiThreeNFourIt is not necessary to consist only of SiC, Si,ThreeNFour, Specifically SiC, SiThreeNFourIs contained in the sintered body by 75% by weight or more.
Note that a SiC sintered body is used when higher thermal conductivity is required as a substrate, and Si is used when impact resistance is required.ThreeNFourIt is preferable to select a sintered material.
[0021]
However, in the present invention, the base material of the support is composed of a Si-SiC sintered body. This is because the Si-SiC sintered body is excellent in thermal conductivity and strength, and can be particularly suitably used as a base material constituting the support of the present invention.
The Si-SiC sintered body refers to a sintered body containing metallic Si and SiC as constituent components. For example, the SiC powder, graphite powder, organic binder and moisture or organic solvent previously disclosed by the present applicant are disclosed. An Si-SiC sintered body formed by firing a molding raw material contained therein and firing the molded body at 1350 to 2500 ° C. in a metal Si atmosphere and in a reduced-pressure inert gas atmosphere or vacuum. (Japanese Patent Laid-Open No. 5-270917).
[0022]
When the Si-SiC sintered body is selected as the base material, if the metal Si content in the sintered body is 2 to 35% by weight, the impact resistance, heat uniformity, and corrosion resistance of the support are improved. preferable. If the metal Si is less than 2% by weight, the corrosion resistance and impact resistance may be lowered, and if it exceeds 35% by weight, the heat uniformity may be inferior.
The metal Si content can be controlled by the amount of metal Si, graphite powder, and pore-forming agent added.
[0023]
The shape of the substrate can be appropriately selected depending on the heating furnace method and the like. For example, in the case of using an induction heating furnace, it is preferable to have a bowl shape (half tube shape) so that an induction current does not flow through the base material. is there.
Further, if a steel plate is rolled, a roller-shaped one may be used.
[0024]
(2) Support layer
The support of the present invention forms a support layer on the surface of the substrate. With such a configuration, the workpiece is supported exclusively by the support layer and does not come into direct contact with SiC or the like constituting the base material. Therefore, the component in the workpiece (for example, lead) or the workpiece itself (for example, iron) Etc.) can be prevented from erosion and wear of the base material (that is, the support).
[0025]
The support layer is required to be made of a material that is at least less reactive with the workpiece than the substrate. In this specification, “reactivity with the workpiece” means the reactivity with the workpiece under the heating and machining conditions (temperature, atmosphere, etc.) of the workpiece, and the reaction with the workpiece itself. The reactivity with the component (for example, low melting-point components, such as lead) in a workpiece other than the property is also included. Specifically, a material that reacts with the workpiece itself or a component in the workpiece to form a low melting point component is not preferable because the support layer is worn out. For example, since silica reacts with lead in the workpiece to produce low melting point lead glass, alumina and metal silicon also react with iron (that is, the workpiece itself) to produce a low melting point component, thus forming a support layer. It is unsuitable as a constituent material.
[0026]
The “material having low reactivity with the workpiece” varies depending on the component composition of the workpiece, the heating / processing conditions, and the like, and therefore, it is necessary to individually select materials that meet the conditions. However, it is assumed that a general billet material and steel plate containing about 0.5% by weight of lead having a low melting point are processed at about 1200 ° C. (hereinafter, such conditions are referred to as “general processing conditions”). In this case, tungsten, zirconium, etc. are used as metals having low reactivity with the work material, and tungsten carbide, zirconia, zircon, spinel, chromium oxide (Cr2OThree) And the like.
[0027]
Furthermore, it may be a mixture of two or more ceramics or metals, such as an alumina-zirconia mixture, an alumina-chromium oxide mixture, or the like. Under general processing conditions, an alumina-zirconia mixture should contain at least 10% by weight of zirconia, and an alumina-chromium oxide mixture should contain at least 5% chromium oxide. It is necessary to be.
[0028]
Regarding the reactivity with the workpiece, place the workpiece on the test piece for a certain period of time under the actual heating and processing conditions (temperature, atmosphere, etc.) and check the degree of alteration of the test piece surface. It can be evaluated comparatively easily by the method.
[0029]
The support layer needs to have a certain thickness in order not to contact the workpiece and the substrate. From such a viewpoint, the thickness of the support layer needs to be at least more than 0.2 mm, preferably 0.5 mm or more, and more preferably 1 mm or more. The form is not particularly limited as long as the workpiece and the base material do not contact each other. For example, a method of forming a single-layer or multi-layer coating, or a support layer by arranging a plurality of plate-like bodies on the surface of the base material And the like. In any of the above forms, the workpiece is supported exclusively by the support layer and does not come into contact with the substrate surface, so that the object of the present invention can be achieved.
[0030]
In the case where the support layer is formed into a film, the support layer can be formed by a conventionally known film forming method such as thermal spraying, CVD, sputtering, vacuum deposition, screen printing, dipping and baking ceramic slurry.
The coating may be a single layer or a multilayer, and for example, the coating 3 may be formed on the inner peripheral surface of a tube-like or bowl-shaped
[0031]
However, in the present invention, the support layer of the support isThermal spray coating formed by thermal sprayingWas. According to thermal spraying, it is possible to form a coating having a thickness of about 0.5 mm, and since the thermal spray coating is formed by injecting metal or ceramic melted at a high temperature of 3000 to 6000 ° C. onto a substrate, the strength of the coating Because it is expensive.
[0032]
As the material for the thermal spray coating, the above-described metals, ceramics, or a mixture of two or more ceramics or metals can be preferably used. In particular, a thermal spray coating made of tungsten, zirconia, or zircon is to be processed. It is preferable in terms of low reactivity with the material. Among them, zircon (ZrSiOFour) Is excellent in wear resistance and corrosion resistance, and has the characteristics that it is difficult to wet the molten metal, so that it can be suitably used as a material constituting the sprayed coating.
The thermal spraying method is not particularly limited, but plasma spraying capable of spraying a high melting point material such as tungsten is preferable.
[0033]
In the present inventionSupport layer is a thermal spray coatingFor, Forming a sprayed coating on a substrate made of a Si-SiC sintered body with a porosity of 2-8%Do.
When the porosity of the substrate is less than 2%, the sprayed coating does not adhere firmly to the substrate, whereas when the porosity exceeds 8%, the thermal conductivity that is characteristic of Si-SiC decreases, This is because if the support is damaged by spalling in a portion where a temperature difference is likely to occur or a local overheating state occurs, the support surface may be deteriorated.
[0034]
A support having a support layer made of a SiC CVD film on the surface of a substrate made of Si-SiC is also preferable. According to CVD, it is possible to form a film having a thickness of about 1 mm, and since the CVD film forms a film by using a chemical reaction, the film is dense, has excellent wear resistance, and works with a workpiece. This is because the reactivity of is low. Forming a SiC CVD film on a substrate made of Si—SiC is particularly preferable in that a support having excellent thermal conductivity and low reactivity with a workpiece can be formed.
[0035]
When the support layer is formed by arranging a plurality of plate-like bodies on the surface of the base material, the plate-like body made of the above-described metal, ceramic, or two or more kinds of ceramics or a mixture of metals is used. That is, it may be arranged on the contact surface with the workpiece.
The method of forming a support layer by disposing a plurality of plate-like bodies on the surface of the base material is preferable in that it can be mechanically fitted or adhered, and the thickness of the support layer can be increased as compared with thermal spraying or CVD.
[0036]
For example, a support layer is formed by sticking a zirconia sintered body, which is a ceramic having low reactivity with a workpiece, to the inner peripheral surface of a tube-like or bowl-like substrate or the surface of a roller-like substrate. be able to.
Examples of the method of attaching the ceramic sintered body to the substrate surface include a method of bonding with an inorganic adhesive such as alumina-silica-sodium silicate and alumina-silica-SiC-aluminum phosphate.
[0037]
The support layer is not necessarily formed so as to cover the entire surface of the substrate surface, and may be intermittently formed on the substrate surface. For example, as shown in FIG. 3 and FIG. 4, it is also possible to form it in the shape of a band or a spot on the substrate surface.
Such a method is preferable in that peeling of the support layer can be prevented because the difference in coefficient of thermal expansion between the support layer and the substrate can be alleviated.
The belt-like or spot-like support layer is formed by, for example, a method of performing thermal spraying by masking the substrate surface with an aluminum plate or the like provided with a slit or hole in a shape complementary to the support layer, a plate-like or spot-like plate on the substrate surface It can be formed by a method of arranging the shaped body.
[0038]
【Example】
Hereinafter, the support of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
[0039]
(Reference example1)
Reference example1 shows the following SiO2Bonded SiC, Si3N4Alternatively, a Si-SiC sintered body having a length of 50 mm, a width of 50 mm, and a thickness of 8 mm is used as a base material, and a support layer is formed on the surface of the base material with various materials. Reactivity was evaluated.
[0040]
▲ 1 ▼ SiO2Bonded SiC: 65% by weight of SiC as an aggregate having an average particle size of 250 μm (maximum particle size of 500 μm) and 100% of a mixture of 35% by weight of fine SiC having an average particle size of 8 μm (maximum particle size of 20 μm), CaO, V as an aid for binder production2OFiveAfter adding 0.5% by weight of each of these, 0.5% by weight of sodium hexametaphosphate as a binder, and 20% by weight of water and mixing, a molded body was obtained by casting using a gypsum mold.
[0041]
The molded body was dried at 80 ° C. for 10 hours and then fired in an oxidizing atmosphere at 1400 ° C. for 5 hours to obtain a sintered body (hereinafter referred to as “sintered body A”). The composition of the sintered body is SiC: SiO2: Other components = 87: 12: 1, the apparent porosity was 8.5%, and the bulk specific gravity was 2.56.
[0042]
▲ 2 ▼ SiThreeNFour: Si with an average particle size of 10 μmThreeNFour95% by weight, sintering aid Y2OThreeAfter adding 30% by weight of water to 100% by weight of the mixture consisting of 5% by weight and mixing, cast molding using a gypsum mold was performed, and further a CIP treatment was performed to obtain a molded body. The molded body was fired at 1900 ° C. in a nitrogen atmosphere to obtain a sintered body (hereinafter referred to as “sintered body B”).
[0043]
(3) Si-SiC: 65% by weight of SiC as an aggregate with an average particle size of 80 μm (maximum particle size 200 μm), 30% by weight of fine SiC with an average particle size of 5 μm (maximum particle size 8 μm), carbon powder 5 After adding and mixing 0.5% by weight of sodium hexametaphosphate and 25% by weight of water as a binder to 100% of the mixture consisting of 100% by weight, a molded product was obtained by casting using a gypsum mold.
[0044]
The molded body was dried at 80 ° C. for 10 hours and then fired in metal Si atmosphere and in vacuum at 1650 ° C. while impregnating metal Si to obtain a sintered body (hereinafter, “sintered body C”). That said.) The composition of the sintered body was SiC: Si = 81: 19, the apparent porosity was 0.2%, and the bulk specific gravity was 2.99.
[0045]
(Comparative Examples 1-1 to 1-3)
Comparative Example 1-1 is a sintered body A, Comparative Example 1-2 is a sintered body B, and Comparative Example 1-3 is a sintered body C having a predetermined shape (length 50 mm × width 50 mm × thickness 8 mm). used.
[0046]
(Reference example1-1)
A thermal spray coating having a film thickness of 500 μm was formed by plasma spraying a tungsten powder having a particle size of 50 to 100 μm on the sample of Comparative Example 1-3.
[0047]
(Reference example1-2)
The sample of Comparative Example 1-3 was plasma sprayed with a metal zirconium powder having a particle size of 10 to 74 μm to form a sprayed coating having a thickness of 500 μm.
[0048]
(Reference example1-3)
Plasma spraying of tungsten carbide powder having a particle size of 20 to 88 μm was performed on the sample of Comparative Example 1-3 to form a sprayed coating having a thickness of 500 μm.
[0049]
(Reference example1-4)
The sample of Comparative Example 1-3 was plasma sprayed with stabilized zirconia (zirconia: yttria weight ratio = 92: 8) powder having a particle size of 30 to 70 μm to form a sprayed coating having a thickness of 500 μm.
[0050]
(Reference example1-5)
Zircon (zirconia: silica weight ratio = 65: 35) powder having a particle size of 10 to 74 μm was plasma sprayed on the sample of Comparative Example 1-3 to form a sprayed coating having a thickness of 500 μm.
[0051]
(Reference example1-6)
The sample of Comparative Example 1-3 was plasma sprayed with spinel (alumina: magnesia weight ratio = 65: 35) powder having a particle size of 50 to 100 μm to form a sprayed coating having a thickness of 500 μm.
[0052]
(Reference example1-7)
The sample of Comparative Example 1-3 was plasma sprayed with a mixed powder of alumina-chromium oxide (weight ratio 93: 7) having a particle size of 44 to 105 μm to form a sprayed coating having a thickness of 500 μm. That is, a sprayed coating of the mixture was formed.
[0053]
(Reference example1-8)
Plasma spraying tungsten powder having a particle size of 50-100 μm to the sample of Comparative Example 1-3 to form a sprayed coating having a thickness of 50 μm, and further mixing of alumina: zirconia having a particle size of 30-70 μm (weight ratio 80:20) The powder was plasma sprayed to form a sprayed coating having a thickness of 300 μm. That is, a multilayer sprayed coating was formed.
[0054]
(Reference example1-9)
For the sample of Comparative Example 1-3, CH, which is a gas for generating SiC4And SiCl4And the mixed gas was reacted at 1300 ° C. to perform a CVD process, and a SiC CVD film having a thickness of 500 μm was formed.
[0055]
(Evaluation)
Reference exampleA billet material of 10 mm length x 10 mm width x 10 mm thickness containing 0.5% by weight of lead was placed on the surface of the comparative sample and held for 8 hours under the temperature conditions listed in Table 1. The reactivity with the billet material was evaluated by visually judging the degree of erosion of the sample surface. The degree of erosion was evaluated as ◎ when no erosion was observed or a slight erosion was observed, ◯ when partial erosion was observed, and × when overall erosion was observed. evaluated. The results are shown in Table 1.
[0056]
[Table 1]
As shown in Table 1, the samples of Comparative Examples 1-1 to 1-3 in which the support layer was not formed at the heating temperature of 1200 ° C. in normal hot working were found to be melted, whereas the support was not supported. Layer formedReference exampleNo melting loss was observed in the samples 1-1 to 1-9.Reference example1-1 (tungsten spraying), 1-4 (zirconia thermal spraying), and 1-5 (zircon thermal spraying) were not damaged even at a high temperature of 1320 ° C.Reference exampleParticularly good results were obtained among the samples.
[0058]
(Reference example2)
Reference exampleIn No. 2, the workpiece was actually reciprocated on the surface of the support to evaluate the degree of melting and wear of the support. As a support,Reference exampleA plate-like sintered body having a length of 250 mm, a width of 100 mm, and a thickness of 8 mm, prepared in the same manner as in Example 1, was used as a base material, and a support layer intermittently formed on the surface of the base material was used.
[0059]
(Comparative Examples 2-1 and 2-2)
In Comparative Example 2-1, the sintered body A was used, and in Comparative Example 2-2, the sintered body C was used in a predetermined shape (length 250 mm × width 100 mm × thickness 8 mm).
[0060]
(Reference example2-1)
The sample of Comparative Example 2-2 is masked with an aluminum slit plate in which slits with a width of 5 mm are provided at intervals of 10 mm, and a tungsten powder having a particle diameter of 50 to 100 μm is plasma sprayed to obtain a width as shown in FIG. Strip-shaped sprayed
[0061]
(Reference example2-2)
The sample of Comparative Example 2-2 was masked with a perforated plate made of aluminum in which holes of 10 mmφ were drilled so as to form an equilateral triangle with a side of 12 mm when connecting the centers of three adjacent holes. Tungsten powder having a diameter of 50 to 100 μm was plasma sprayed to form a sprayed
[0062]
(Reference example2-3)
As shown in FIG. 5, the sample of Comparative Example 2-2 was stabilized zirconia (zirconia: yttria weight) having a shape of length 10 mm × width 10 mm ×
[0063]
(Evaluation)
Reference exampleA plate-like billet material having a length of 50 mm, a width of 100 mm and a thickness of 20 mm containing 0.5% by weight of lead is placed on the surface of the sample of the comparative example.2: N2The sample was heated to 1300 ° C. in an electric furnace having a weight ratio of 5:95 and reciprocated at a speed of 20 mm / sec for 100 hours to evaluate the degree of wear on the sample surface. When the wear on the surface of the support was 0.1 mm or less, it was evaluated as ◎, when it was 0.1 to 1 mm, it was evaluated as ○, and when it was more than 1 mm, it was evaluated as ×. The results are shown in Table 2.
The billet material was evaluated while being replaced every 5 hours in order to avoid the influence of structural changes due to oxidation.
[0064]
[Table 2]
As a result, as shown in Table 2, in Comparative Examples 2-1 and 2-2, wear exceeding 1 mm in thickness was recognized,Reference exampleThe wear of 2-1 and 2-2 was hardly recognized as being 0.1 mm or less in thickness, and good results were shown.Reference exampleAlthough 2-3 is somewhat worn, it is a sufficiently practical level, and it can be expected that the service life in the actual machine is twice or more that of Comparative Example 2-1 (about 1 to 2 months).
[0066]
(Example 3)
In Example 3, the workpiece was actually reciprocated on the surface of the support to evaluate the degree of melting and wear of the support. The support isReference example1 is used as a base material (hereinafter referred to as “sintered body D”). The base is a saddle-like Si—SiC sintered body obtained by halving a hollow tube having a length of 200 mm, an inner diameter of 68 mmφ, and an outer diameter of 80 mmφ. ), A substrate having a support layer formed on the surface thereof. However, the base material was produced not by casting but by extrusion.Sintered body DThe weight ratio of SiC: Si was 80:20, and the apparent porosity of the sintered body was 2.5%.
[0067]
(Comparative Example 3-1)
The sintered body D was used as it was without forming a support layer.
[0068]
(Example 3-1)
Plasma spraying of stabilized zirconia (zirconia: yttria weight ratio = 92: 8) powder having a particle size of 30 to 70 μm to the sintered body D forms a sprayed
[0069]
(Example 3-2)
The sintered body D is masked with an aluminum slit plate in which slits having a width of 5 mm are provided at intervals of 2 mm, and plasma spraying of zirconia (zirconia: calcia weight ratio = 96: 4) powder having a particle size of 30 to 70 μm is performed. As shown in FIG. 6B, strip-shaped sprayed
[0070]
(Example 3-3)
The sintered body D was masked with a perforated plate made of aluminum in which holes of 10 mmφ were formed so as to form a regular triangle of 12 mm on each side when connecting the centers of three adjacent holes.1-1Thermal spraying was performed in the same manner as in FIG. 6 to form a sprayed
[0071]
(Reference Example 3-1)
For the sintered body D, CH, which is a gas for generating SiC4And SiCl4The mixed gas was reacted at 1300 ° C. to perform a CVD process, and a SiC CVD film having a thickness of 500 μm was formed as shown in FIG.
[0072]
(Evaluation)
ExampleReference examplesUsing a cylindrical billet material having a length of 100 mm and an outer diameter of 55 mmφ containing 0.5% by weight of lead on the surface of the sample of the comparative example,Reference exampleThe amount of wear on the sample surface was evaluated in the same manner as in 2. When the wear on the surface of the support was 0.1 mm or less, it was evaluated as ◎, when it was 0.1 to 1.0 mm, it was evaluated as ○, and when it was over 1.0 mm, it was evaluated as ×. The results are shown in Table 3.
The billet material was evaluated while being replaced every 5 hours in order to avoid the influence of structural changes due to oxidation.
[0073]
[Table 3]
As a result, as shown in Table 3, the support of Comparative Example 3-1 was found to have wear exceeding 2.5 mm in thickness, whereas Examples 3-1 to3-3, Reference Example 3-1The support of No. 5 showed good results with almost no wear of 0.5 mm or less.
[0075]
Example 4
In Example 4, the influence of the porosity of the Si—SiC sintered body on the thermal conductivity of the support and the fixing strength of the sprayed coating was evaluated. Even in Example 4,Reference exampleA Si—SiC sintered body produced by the same method as in No. 1 was cut into a length of 50 mm × width of 50 mm × thickness of 8 mm as a base material. However, by adjusting the amount of impregnation of metal Si during firing, 7-level base materials having different apparent porosity within a range of 0.3 to 10% were prepared. The substrate was plasma sprayed with stabilized zirconia (zirconia: yttria weight ratio = 92: 8) powder having a particle size of 30 to 70 μm to form a sprayed coating having a thickness of 500 μm.
[0076]
As shown in FIG. 7, the fixing strength between the base material and the sprayed coating is such that the flat plate portion (20 mm × 20 mm) of the measuring
The results are shown in Table 4.
[0077]
[Table 4]
As shown in Table 4, when the apparent porosity of the Si—SiC sintered body was within the range of the present invention (2 to 8%), both the thermal conductivity and the adhesion strength of the sprayed coating were good. On the other hand, when the apparent porosity is less than 2%, the sprayed coating is not firmly fixed, and when the apparent porosity is more than 8%, the thermal conductivity is lowered.
[0079]
【The invention's effect】
As described above, the support of the present invention isSi-SiC sintered body having a predetermined porosityA material having a low reactivity with a workpiece compared to the base material on the surface of the base material made ofSprayed coatingSince the support layer made of is formed, it has heat resistance, strength, impact resistance, corrosion resistance, wear resistance, low specific heat and high thermal conductivity necessary for the support and can prevent the support from being melted and worn.
Therefore, it can be suitably used as, for example, a furnace core tube or a rolling roller of a combustion heating furnace or induction heating furnace.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view (a) and (b) showing one embodiment of a support for hot working according to the present invention.
FIG. 2 is a longitudinal sectional view showing a form of an induction heating furnace.
FIG. 3 is a schematic perspective view showing an embodiment of the hot working support of the present invention.
FIG. 4 is a schematic perspective view showing an embodiment of the hot working support of the present invention.
FIG. 5 is a schematic perspective view showing an embodiment of the hot working support of the present invention.
FIG. 6 is a schematic perspective view (a), (b), (c) showing an embodiment of the hot working support of the present invention.
FIGS. 7A and 7B are schematic explanatory views showing a test method for fixing strength of a support layer, in which FIG. 7A is a side view and FIG. 7B is a perspective view.
[Explanation of symbols]
DESCRIPTION OF
Claims (5)
前記基材が気孔率２〜８％の金属珪素含浸炭化珪素質の焼結体からなり、
前記支持層が、前記基材に比して被加工材との反応性が低い材質の溶射被膜からなることを特徴とする熱間加工用支持体。 A base material for hot working comprising a base material made of a sintered metal carbide-impregnated silicon carbide, and a support layer formed on the surface of the base material for supporting a workpiece. There,
The substrate is made of a metal silicon impregnated silicon carbide sintered body having a porosity of 2 to 8%,
A support for hot working, wherein the support layer is made of a sprayed coating made of a material that is less reactive with the workpiece than the substrate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23569299A JP4175745B2 (en) | 1999-08-23 | 1999-08-23 | Hot working support |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23569299A JP4175745B2 (en) | 1999-08-23 | 1999-08-23 | Hot working support |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001066071A JP2001066071A (en) | 2001-03-16 |
| JP4175745B2 true JP4175745B2 (en) | 2008-11-05 |
Family
ID=16989817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23569299A Expired - Lifetime JP4175745B2 (en) | 1999-08-23 | 1999-08-23 | Hot working support |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4175745B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006010223A (en) * | 2004-06-25 | 2006-01-12 | Tdk Corp | Sheath for ceramic firing |
-
1999
- 1999-08-23 JP JP23569299A patent/JP4175745B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001066071A (en) | 2001-03-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10519069B2 (en) | Roller for a roller furnace having at least one coating on the surface | |
| JPS61262625A (en) | Protective pipe for thermocouple and its preparation | |
| JP4175745B2 (en) | Hot working support | |
| US3832273A (en) | Composite refractory articles | |
| JP2006183972A (en) | Baking fixture for electronic component | |
| JPH05287475A (en) | Continuous hot dip metal coating device and method therefor | |
| JP2002316877A (en) | Burning tool for electronic parts | |
| JP4270739B2 (en) | Hot working support | |
| KR20040082399A (en) | Articles for casting applications comprising ceramic composite and methods for making articles thereof | |
| JPS58204884A (en) | Ceramic roll | |
| JP3597641B2 (en) | Refractories for metal refining and casting | |
| JPH0657873B2 (en) | Roll for heat treatment furnace | |
| JPH1024351A (en) | Nozzle for continuous casting for steel | |
| JPH08117984A (en) | Sliding nozzle plate refractories | |
| JP2004238215A (en) | Silicon carbide based sintered member having non-reactive sprayed film and method of manufacturing the same | |
| JP2004183011A (en) | Roll for continuous hot dip metal plating | |
| JPH07305155A (en) | Sink roll for molten metal plating | |
| JP3587493B2 (en) | Composite sintered body of boron nitride and spinel | |
| JP5822705B2 (en) | Ceramic composite and sliding member for molten metal plating bath using the same | |
| JP2651834B2 (en) | High heat resistance roll | |
| JP4701380B2 (en) | Aluminum melt member and method for producing the same | |
| JP3076888B2 (en) | 2 melting point heat-resistant sprayed material and heat-resistant member processed by thermal spraying | |
| JPH0269627A (en) | Protective tube for thermocouple | |
| JPH09318459A (en) | Protective tube for molten-metal temperature sensor | |
| JPH04302992A (en) | Refractory material for burning ceramics |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050128 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070306 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080401 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080528 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080812 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080819 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110829 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4175745 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120829 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130829 Year of fee payment: 5 |
|
| EXPY | Cancellation because of completion of term |