JPH0742551B2 - Ferritic heat-resistant cast steel with excellent castability - Google Patents
Ferritic heat-resistant cast steel with excellent castabilityInfo
- Publication number
- JPH0742551B2 JPH0742551B2 JP3294161A JP29416191A JPH0742551B2 JP H0742551 B2 JPH0742551 B2 JP H0742551B2 JP 3294161 A JP3294161 A JP 3294161A JP 29416191 A JP29416191 A JP 29416191A JP H0742551 B2 JPH0742551 B2 JP H0742551B2
- Authority
- JP
- Japan
- Prior art keywords
- cast steel
- content
- weight
- heat
- castability
- 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
- 229910001208 Crucible steel Inorganic materials 0.000 title claims description 22
- 239000012535 impurity Substances 0.000 claims description 6
- 229910052717 sulfur Inorganic materials 0.000 claims description 5
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 239000011651 chromium Substances 0.000 description 23
- 238000005266 casting Methods 0.000 description 16
- 239000010955 niobium Substances 0.000 description 12
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 10
- 230000003647 oxidation Effects 0.000 description 8
- 238000007254 oxidation reaction Methods 0.000 description 8
- 239000011572 manganese Substances 0.000 description 7
- 229910000859 α-Fe Inorganic materials 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 239000011159 matrix material Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000009466 transformation Effects 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 229910045601 alloy Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 3
- 229910001562 pearlite Inorganic materials 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910001018 Cast iron Inorganic materials 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 229910052758 niobium Inorganic materials 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 208000025599 Heat Stress disease Diseases 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 238000003287 bathing Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
Landscapes
- Exhaust Silencers (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、エンジンのエキゾース
トマニホールド等を鋳鋼で製造することを可能とする鋳
造性が優れたフェライト系耐熱鋳鋼に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferritic heat-resistant cast steel which is excellent in castability and which enables production of engine exhaust manifolds and the like from cast steel.
【０００２】[0002]
【従来の技術】自動車エンジンのエキゾーストマニホー
ルドは、従前、鋳鉄で製造されていたが、近時の排ガス
規制の強化及びエンジン性能の向上等の要求の下で、排
気温度が高くなっているため、耐熱性及び耐酸化性の点
で問題があった。そこで、鋳鉄の替わりに、ステンレス
鋼等の耐熱鋼が使用されるようになった。この自動車エ
ンジンのエキゾーストマニホールド用の耐熱鋳鋼とし
て、従来、ＡＳＴＭＳＵＳ４０９又はＳＵＳ４３０等の
フェライト系ステンレス鋼が使用されており、また、特
開昭64-8254 に開示されたフェライト系ステンレス鋼が
提案されている。これらの耐熱鋳鋼の組成（重量％）を
下記表１に示す。2. Description of the Related Art Exhaust manifolds for automobile engines have been manufactured from cast iron for a long time. There was a problem in terms of heat resistance and oxidation resistance. Therefore, heat-resistant steel such as stainless steel has come to be used in place of cast iron. As a heat-resistant cast steel for the exhaust manifold of this automobile engine, ferritic stainless steel such as ASTM S409 or SUS430 has been conventionally used, and ferritic stainless steel disclosed in JP-A-64-8254 has been proposed. . The compositions (wt%) of these heat resistant cast steels are shown in Table 1 below.
【０００３】[0003]
【表１】 [Table 1]
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、上述し
た従来の耐熱鋳鋼を使用して、自動車のエキゾーストマ
ニホールド等のように、薄肉で形状が複雑な鋳物を製造
する場合には、その鋳型内に溶湯を鋳込む際に吸引し、
又は加圧して、湯回り不良の改善を図っている。このた
め、鋳造装置が大掛かりになると共に、生産性が悪いと
いう欠点がある。本発明はかかる問題点に鑑みてなされ
たものであって、耐熱性及び耐酸化性等のエキゾースト
マニホールド用材としての特性が優れていると共に、鋳
造性が改善され、吸引等の付加的手段を不要とするた鋳
造性が優れたフェライト系耐熱鋳鋼を提供することを目
的とする。However, when a thin and complex casting such as an automobile exhaust manifold is manufactured by using the above-mentioned conventional heat-resistant cast steel, the molten metal is placed in the mold. Suction when casting,
Alternatively, pressurization is applied to improve the poor bathing. Therefore, there are disadvantages that the casting apparatus becomes large-scale and the productivity is poor. The present invention has been made in view of the above problems, and has excellent properties as an exhaust manifold material such as heat resistance and oxidation resistance, improved castability, and does not require additional means such as suction. It is an object of the present invention to provide a ferritic heat-resistant cast steel having excellent castability.
【０００５】[0005]
【課題を解決するための手段】本発明に係る鋳造性が優
れたフェライト系耐熱鋳鋼は、Ｃ：０．０６乃至０．１
５重量％、Ｓｉ：１．０乃至２．３重量％、Ｍｎ：１．
０重量％以下、Ｃｒ：１１．０乃至１３．０重量％及び
Ｎｂ：０．６乃至１．５重量％を含有し、不純物として
のＰ及びＳを夫々０．０４重量％以下に規制し、残部が
Ｆｅ及び不可避的不純物であることを特徴とする。The heat-resistant, ferritic cast steel having excellent castability according to the present invention is C: 0.06 to 0.1.
5% by weight, Si: 1.0 to 2.3% by weight, Mn: 1.
0 wt% or less, Cr: 11.0 to 13.0 wt% and Nb: 0.6 to 1.5 wt%, and P and S as impurities are restricted to 0.04 wt% or less, respectively. The balance is Fe and inevitable impurities.
【０００６】[0006]
【作用】以下、本発明について更に詳細に説明する。本
発明は、上記組成範囲にすることにより、耐熱性及び耐
酸化性を確保しつつ、湯廻り性を改善し、鋳造性を高め
たものである。また、鋳鋼をフェライト基地にすること
により、従来の耐熱鋳鋼がもつ機械加工性を劣化させる
ことなく、その生産性の向上を図った。即ち、フェライ
ト基地の場合は、熱膨張量が少ないこと、オーステナイ
ト系に比べて安価であること、加工性が優れているこ
と、パーライトの分解がないため変態の膨張が少ないこ
と、熱伝導率が優れていること等の利点がある。The present invention will be described in more detail below. In the present invention, the heat resistance and the oxidation resistance are ensured, and the hot-rollability is improved and the castability is enhanced by adjusting the composition within the above range. In addition, by using a ferrite base for the cast steel, the productivity was improved without deteriorating the machinability of the conventional heat-resistant cast steel. That is, in the case of a ferrite matrix, the amount of thermal expansion is small, the cost is lower than that of an austenite type, the workability is excellent, the expansion of transformation is small because there is no decomposition of pearlite, and the thermal conductivity is There are advantages such as being excellent.
【０００７】次に、先ず、本願発明における各成分の添
加理由及び組成限定理由について説明する。Next, the reason for adding each component and the reason for limiting the composition in the present invention will be described.
【０００８】Ｃ（炭素） Ｃは鋳鋼の耐熱性及び耐酸化性を確保するためには可及
的に低くする必要があるが、流動性及び強度を確保して
大気中での鋳造性を良くするために、０．０６重量％以
上含有する。 C (carbon) C needs to be made as low as possible in order to secure the heat resistance and oxidation resistance of cast steel, but the fluidity and strength are secured to improve castability in the atmosphere. Therefore, 0.06% by weight or more is contained.
【０００９】一方、Ｃ含有量が０．１５重量％を超える
と、α−γ相変態が生じ、γ相になりやすい。また、Ｃ
含有量が多いと、Ｃｒの炭化物が生成しやすくなり、こ
れにより、耐酸化性、耐食性及び加工性が低下してしま
う。このため、Ｃ含有量は０．１５重量％以下にする必
要がある。On the other hand, if the C content exceeds 0.15% by weight, the α-γ phase transformation occurs and the γ phase is likely to be formed. Also, C
When the content is high, Cr carbides are likely to be generated, which deteriorates oxidation resistance, corrosion resistance and workability. Therefore, the C content needs to be 0.15% by weight or less.
【００１０】Ｓｉ（珪素） Ｓｉはフェライト組織を安定化すると共に、耐酸化性及
び鋳造性を高める作用がある。また、脱酸効果があるの
で、ピンホール欠陥を抑制する。Ｓｉ含有量が１．０重
量％未満の場合は、このような効果が得られない。一
方、Ｓｉ含有量が２．３重量％を超えると、Ｃとの協働
作用により一次炭化物が粗大化し、靱性が低下する。 Si (Si) Si has the functions of stabilizing the ferrite structure and enhancing oxidation resistance and castability. Further, since it has a deoxidizing effect, it suppresses pinhole defects. If the Si content is less than 1.0% by weight, such an effect cannot be obtained. On the other hand, when the Si content exceeds 2.3% by weight, the primary carbide is coarsened due to the synergistic action with C, and the toughness is reduced.
【００１１】Ｍｎ（マンガン） Ｍｎは脱酸効果、湯流れ性、Ｎ親和性及び加工性を向上
させる作用がある。しかし、Ｍｎは基地をパーライト化
する元素である。このため、Ｍｎの含有量の上限値は
１．０重量％に規制する。 Mn (Manganese) Mn has an effect of improving the deoxidizing effect, the melt flowability, the N affinity and the workability. However, Mn is an element that makes the matrix pearlite. Therefore, the upper limit of the Mn content is limited to 1.0% by weight.
【００１２】Ｐ（リン） Ｐはパーライト及びステダイトを生成して加工性を低下
させる成分である。また、Ｐの含有は、耐食性及び耐熱
疲労性を低下させる。このため、不純物としてのＰの含
有量は０．０４重量％以下に規制する。 P (Phosphorus) P is a component that forms pearlite and steadite to reduce the processability. Further, the inclusion of P reduces the corrosion resistance and the thermal fatigue resistance. Therefore, the content of P as an impurity is restricted to 0.04% by weight or less.
【００１３】Ｓ（硫黄）鋳鋼中にＳが含まれると、Ｍｎ
Ｓの生成による加工性の改善が期待できるが、 Ｓは鋳鋼の耐食性及び耐熱疲労性を低下させてしまう。
このため、不純物としてのＳの含有量は、０．０４重量
％以下に規制する。If S is contained in S (sulfur) cast steel, Mn
Although the workability can be improved by the generation of S, S deteriorates the corrosion resistance and heat fatigue resistance of the cast steel.
Therefore, the content of S as an impurity is regulated to 0.04% by weight or less.
【００１４】Ｃｒ（クロム） Ｃｒは鋳鋼の表面に酸化性の不動態皮膜を生成して耐酸
化性を向上させると共に、共析変態温度を向上させる作
用を有する。これにより、鋳鋼の基地のフェライト化率
が高くなる。図１は横軸にＣｒ含有量（重量％）をと
り、縦軸にフェライト率（％）をとって、Ｃｒ含有量と
フェライト率との関係を示すグラフ図である。この図に
示すように、Ｃｒ含有量の増加と共に、フェライト率が
上昇する。Ｃｒ含有量が１１．０重量％未満の場合は、
このような効果が得られない。 Cr (Chromium) Cr has an action of forming an oxidative passivation film on the surface of the cast steel to improve the oxidation resistance and also to improve the eutectoid transformation temperature. This increases the ferritic conversion rate of the cast steel matrix. FIG. 1 is a graph showing the relationship between the Cr content and the ferrite ratio, with the Cr content (% by weight) on the horizontal axis and the ferrite ratio (%) on the vertical axis. As shown in this figure, the ferrite ratio rises as the Cr content increases. When the Cr content is less than 11.0% by weight,
Such an effect cannot be obtained.
【００１５】一方、Ｃｒ含有量が１３．０重量％を超え
ると、鋳造性が低下すると共に、Ｃｒの一次炭化物が粗
大化するため好ましくない。図２は横軸にＣｒ含有量
（重量％）をとり、縦軸に湯流れ量（ｃｍ）をとって、
Ｃｒ含有量と湯流れ量との関係を示すグラフ図である。
この図に示すように、Ｃｒ含有量が増加すると、湯流れ
性が低下する。On the other hand, when the Cr content exceeds 13.0% by weight, the castability is deteriorated and the primary carbide of Cr is coarsened, which is not preferable. In FIG. 2, the horizontal axis represents the Cr content (% by weight), and the vertical axis represents the molten metal flow rate (cm).
It is a graph which shows the relationship between Cr content and molten metal flow rate.
As shown in this figure, when the Cr content increases, the flowability of the molten metal decreases.
【００１６】また、Ｃｒの含有量が多くなると、耐酸化
性試験において、鉄酸化層が薄くなる。図３は横軸にＣ
ｒ含有量をとり、縦軸に鋳鋼の鉄酸化層の厚さ（μｍ）
をとって、Ｃｒ含有量と鉄酸化層厚さとの関係を示すグ
ラフ図である。この図に示すように、Ｃｒ含有量が増加
すると、鉄酸化層の厚さが薄くなる。このため、Ｃｒ含
有量は１１．０乃至１３．０重量％とする。When the Cr content is high, the iron oxide layer becomes thin in the oxidation resistance test. Figure 3 shows C on the horizontal axis
r content is taken and the vertical axis is the thickness of iron oxide layer of cast steel (μm)
FIG. 5 is a graph showing the relationship between the Cr content and the iron oxide layer thickness. As shown in this figure, as the Cr content increases, the iron oxide layer becomes thinner. Therefore, the Cr content is 11.0 to 13.0% by weight.
【００１７】Ｎｂ（ニオブ） Ｎｂは鋳鋼の基地のフェライト化を促進する。そして、
Ｎｂは微細なＮｂ炭化物として析出し、耐熱鋳鋼の高温
強度を向上させる。また、Ｎｂが炭化物として析出する
ことにより、Ｃｒ炭化物の析出が抑制される。これによ
り、鋳鋼の耐食性及び加工性が向上する。更に、Ｎｂの
添加は鋳鋼の結晶粒を微細化し、鋳鋼の強度及び靱性を
向上させる。更にまた、Ｎｂは炭素（Ｃ）及び窒素
（Ｎ）との親和力が強いため、Ｃｒの窒化物及び炭化物
の生成による強度及び靱性の低下を防止できる。このよ
うな効果を得るためには、Ｎｂ含有量を０．６重量％以
上にする必要がある。 Nb (Niobium) Nb promotes ferritic transformation of the matrix of cast steel. And
Nb precipitates as fine Nb carbide and improves the high temperature strength of the heat resistant cast steel. In addition, the precipitation of Cr carbide is suppressed by the precipitation of Nb as carbide. This improves the corrosion resistance and workability of cast steel. Furthermore, the addition of Nb refines the crystal grains of the cast steel and improves the strength and toughness of the cast steel. Furthermore, since Nb has a strong affinity with carbon (C) and nitrogen (N), it is possible to prevent a decrease in strength and toughness due to the formation of nitrides and carbides of Cr. In order to obtain such an effect, the Nb content needs to be 0.6% by weight or more.
【００１８】一方、Ｎｂを多量に添加すると、結晶粒界
に炭化物が形成され、靱性が低下する。このため、Ｎｂ
含有量の上限値は１．５重量％にする必要がある。On the other hand, when a large amount of Nb is added, carbide is formed at the crystal grain boundaries and the toughness is lowered. Therefore, Nb
The upper limit of the content must be 1.5% by weight.
【００１９】鋳込温度及び鋳込み流量 鋳込み温度は、１５５０乃至１６４０℃、また、鋳込み
流量（ｋｇ／秒）は、５．８ｋｇ／秒以上にすることが
好ましい。図４は湯廻り不良に及ぼす鋳込み温度（℃）
及び鋳込み流量（ｋｇ／秒）の影響を示すグラフ図であ
る。図中、●及び◆が本実施例の合金で、●が湯廻り不
良が生じなかった場合、◆が湯廻り不良が生じた場合の
データである。また、黒三角印はＳＵＳ４３０合金の場
合のデータである。 Casting temperature and casting flow rate The casting temperature is preferably 1550 to 1640 ° C., and the casting flow rate (kg / sec) is preferably 5.8 kg / sec or more. Figure 4 shows the casting temperature (° C) that affects the hot-water flow defect.
It is a graph showing the influence of the casting flow rate (kg / sec). In the figure, ● and ◆ are the alloys of the present embodiment, ● is the data when no hot water flow failure occurred, and ◆ is the data when hot water flow failure occurred. The black triangles are the data for SUS430 alloy.
【００２０】この図４から明らかなように、本実施例に
おいては、鋳込温度が１５５０℃という比較的低温で
も、良好な湯廻り性が得られる。これに対し、従来のＳ
ＵＳ４３０合金は１７２０℃の鋳込み温度が必要であ
る。As is apparent from FIG. 4, in the present embodiment, good meltability can be obtained even at a relatively low casting temperature of 1550 ° C. In contrast, conventional S
US430 alloy requires a casting temperature of 1720 ° C.
【００２１】[0021]
【実施例】次に、本発明の実施例について説明する。EXAMPLES Next, examples of the present invention will be described.
【００２２】下記表１は本発明の実施例及び比較例の組
成を示す。また、表２はこれらの鋳鋼を使用してエキゾ
ーストマニホールドを製造した場合の、鋳造条件及び得
られた鋳造製品の品質を示す。Table 1 below shows the compositions of Examples and Comparative Examples of the present invention. In addition, Table 2 shows the casting conditions and the quality of the obtained cast product when an exhaust manifold is manufactured using these cast steels.
【００２３】この表１から明らかなように、本発明の特
許請求の範囲に入る実施例１〜１１は肉厚が２．５〜
３．０ｍｍ、３．０〜３．５ｍｍと薄い場合でも、ま
た、鋳込温度が１６４０℃以下と低い場合でも、湯ざか
い等が発生せず、鋳造性が極めて優れていた。これに対
し、その比較例１〜１０の場合は、鋳込み温度を１６８
０℃以上に高くする必要があり、また、それでも湯ざか
いが発生していた。As is apparent from Table 1, Examples 1 to 11 which fall within the scope of the claims of the present invention have a wall thickness of 2.5 to
Even when it was as thin as 3.0 mm and 3.0 to 3.5 mm, and when the casting temperature was as low as 1640 ° C. or lower, no hot water or the like was generated and the castability was extremely excellent. On the other hand, in Comparative Examples 1 to 10, the casting temperature was 168
It was necessary to raise the temperature to 0 ° C. or higher, and still the hot water was still generated.
【００２４】なお、本発明材は格別熱処理を施さなくて
も十分な強度及び靱性を具備している。しかし、鋳造品
に対して、固溶化熱処理及び焼きなまし処理を施しても
よいことは勿論である。The material of the present invention has sufficient strength and toughness without any special heat treatment. However, it goes without saying that the cast product may be subjected to solution heat treatment and annealing treatment.
【００２５】[0025]
【表１】 [Table 1]
【００２６】[0026]
【表２】 [Table 2]
【００２７】[0027]
【発明の効果】本発明によれば、耐熱性及び強度が優れ
ていると共に、鋳込み性が極めて優れた耐熱鋳鋼を得る
ことができる。このため、生砂の鋳型を使用して吸引を
することなく、エキゾーストマニホールドのような薄肉
の複雑形状の鋳物も高生産性で製造することができ、高
品質の鋳物製品を得ることができる。According to the present invention, it is possible to obtain a heat-resistant cast steel which is excellent in heat resistance and strength and is extremely excellent in castability. Therefore, it is possible to produce a thin-walled casting having a complicated shape such as an exhaust manifold with high productivity without using a mold of raw sand, and to obtain a high-quality casting product.
【図面の簡単な説明】[Brief description of drawings]
【図１】Ｃｒ含有量とフェライト率との関係を示すグラ
フ図である。FIG. 1 is a graph showing the relationship between Cr content and ferrite ratio.
【図２】Ｃｒ含有量と湯流れ量との関係を示すグラフ図
である。FIG. 2 is a graph showing a relationship between a Cr content and a molten metal flow rate.
【図３】Ｃｒ含有量と鉄酸化層厚さとの関係を示すグラ
フ図である。FIG. 3 is a graph showing the relationship between Cr content and iron oxide layer thickness.
【図４】鋳込み温度及び鋳込み流量と湯廻り不良との関
係を示すグラフ図である。FIG. 4 is a graph showing a relationship between a pouring temperature and a pouring flow rate and a defective molten metal distribution.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭58−64355（ＪＰ，Ａ) 特開 昭64−8254（ＪＰ，Ａ) 特公 昭43−17077（ＪＰ，Ｂ２) ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-58-64355 (JP, A) JP-A-64-8254 (JP, A) JP-B-43-17077 (JP, B2)
Claims (1)
ｉ：１．０乃至２．３重量％、Ｍｎ：１．０重量％以
下、Ｃｒ：１１．０乃至１３．０重量％及びＮｂ：０．
６乃至１．５重量％を含有し、不純物としてのＰ及びＳ
を夫々０．０４重量％以下に規制し、残部がＦｅ及び不
可避的不純物であることを特徴とする鋳造性が優れたフ
ェライト系耐熱鋳鋼。1. C: 0.06 to 0.15% by weight, S
i: 1.0 to 2.3% by weight, Mn: 1.0% by weight or less, Cr: 11.0 to 13.0% by weight, and Nb: 0.
6 to 1.5% by weight, P and S as impurities
Are controlled to 0.04% by weight or less, and the balance is Fe and inevitable impurities, and the heat-resistant ferritic cast steel has excellent castability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3294161A JPH0742551B2 (en) | 1991-11-11 | 1991-11-11 | Ferritic heat-resistant cast steel with excellent castability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3294161A JPH0742551B2 (en) | 1991-11-11 | 1991-11-11 | Ferritic heat-resistant cast steel with excellent castability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06128692A JPH06128692A (en) | 1994-05-10 |
| JPH0742551B2 true JPH0742551B2 (en) | 1995-05-10 |
Family
ID=17804109
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3294161A Expired - Lifetime JPH0742551B2 (en) | 1991-11-11 | 1991-11-11 | Ferritic heat-resistant cast steel with excellent castability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0742551B2 (en) |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62151548A (en) * | 1985-12-26 | 1987-07-06 | Toyota Motor Corp | Heat resistance ferritic high-cr cast steel |
| JPH07113139B2 (en) * | 1987-10-14 | 1995-12-06 | 日産自動車株式会社 | Exhaust manifold and automobile turbine housing with excellent castability and heat fatigue resistance |
-
1991
- 1991-11-11 JP JP3294161A patent/JPH0742551B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06128692A (en) | 1994-05-10 |
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