JP2934424B2 - Steel for free-cutting plastic molds with excellent finished surface roughness - Google Patents
Steel for free-cutting plastic molds with excellent finished surface roughnessInfo
- Publication number
- JP2934424B2 JP2934424B2 JP1638798A JP1638798A JP2934424B2 JP 2934424 B2 JP2934424 B2 JP 2934424B2 JP 1638798 A JP1638798 A JP 1638798A JP 1638798 A JP1638798 A JP 1638798A JP 2934424 B2 JP2934424 B2 JP 2934424B2
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- JP
- Japan
- Prior art keywords
- steel
- graphite
- surface roughness
- finished surface
- free
- 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.)
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- Moulds For Moulding Plastics Or The Like (AREA)
Description
【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【０００１】[0001]
【発明の属する技術分野】本発明は、切削加工における
仕上げ面粗さに優れ、安価に提供することができるプラ
スチック成形金型用の鋼に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to steel for a metal mold for plastic molding, which has excellent finished surface roughness in cutting and can be provided at low cost.
【０００２】[0002]
【従来の技術】従来、自動車のインナーパネルやテレビ
等、大型のプラスチック製部品を成形するために使用す
る金型を製作する際に、加工費を削減してコストダウン
を図るため、被削性を重視した快削鋼が用いられてい
る。すなわち、従来のこの種の金型は被削性を最も重要
視し、Ｐｂ，Ｔｅ，Ｂｉ，Ｃａ，Ｚｒ，Ｓ等の快削成分
を単独または複合添加して、被削性の向上を図ってい
る。2. Description of the Related Art Conventionally, when manufacturing a mold used for molding a large plastic part such as an inner panel of an automobile or a television, the machining cost is reduced by reducing the processing cost. Free-cutting steel with emphasis on is used. That is, in this type of conventional mold, machinability is regarded as the most important, and free-cutting components such as Pb, Te, Bi, Ca, Zr, and S are added alone or in combination to improve machinability. ing.
【０００３】しかし、Ｓ系の快削金型用鋼は機械的性質
が劣化し、異方性を増加する恐れがある。またＰｂ系の
快削金型用鋼は機械的性質を劣化させずに被削性を向上
させることはできるが、Ｐｂは人体に有害であり、また
鋼材のリサイクルの面からも問題がある。更に又、Ｔ
ｅ，Ｂｉ，Ｚｒを添加したものはコストダウンの目的に
反し経済的でない。[0003] However, the mechanical properties of S-based steel for free-cutting dies may deteriorate, and the anisotropy may increase. Pb-based steel for free-cutting dies can improve machinability without deteriorating mechanical properties, but Pb is harmful to the human body and poses a problem in terms of recycling steel materials. Furthermore, T
Addition of e, Bi and Zr is not economical against the purpose of cost reduction.
【０００４】そこで、新たな快削金型用鋼の開発がが要
望されていたが、新たな快削要素として黒鉛が注目さ
れ、例えば特公昭５３−１５４５０号公報及び特公昭５
４−５３６７号公報には、黒鉛を切欠効果、潤滑効果に
利用することで被削性を改良した構造用鋼が提案されて
いる。しかし、前記公報に開示された発明は、鋼中のＣ
を黒鉛化するための黒鉛化処理に長時間を要し、経済的
とは言えないといった問題点がある。Therefore, there has been a demand for the development of a new free-cutting die steel. However, graphite has attracted attention as a new free-cutting element.
Japanese Patent Application Laid-Open No. 4-5367 proposes a structural steel in which machinability is improved by using graphite for a notch effect and a lubrication effect. However, the invention disclosed in the above-mentioned publication discloses that C in steel
However, there is a problem that it takes a long time for the graphitization treatment for graphitizing the material, which is not economical.
【０００５】[0005]
【発明が解決しようとする課題】このような問題点を解
決するため、特開平７−１８８８５０号公報及び特開平
８−２６００９４号公報では、黒鉛化処理を容易にした
黒鉛鋼の製造方法が提案されている。この方法を採用す
ることにより黒鉛化処理時間は短縮されるが、まだ経済
的に十分ではない。また、前記発明で開示された黒鉛鋼
をプラスチック成形金型用鋼として用いた場合、被削性
は改善されるが、黒鉛析出による仕上げ面粗さの劣化は
免れない、といった問題点がある。In order to solve such a problem, Japanese Patent Application Laid-Open Nos. Hei 7-188850 and Hei 8-26,094 propose a method for producing a graphitized steel which can be easily graphitized. Have been. Although the graphitization time is reduced by adopting this method, it is not yet economically sufficient. Further, when the graphite steel disclosed in the above invention is used as a steel for plastic molding dies, machinability is improved, but there is a problem that deterioration of the finished surface roughness due to graphite precipitation is inevitable.
【０００６】[0006]
【課題を解決するための手段】本発明は、上記のような
従来の諸問題点を解決するために成されたもので、仕上
げ面粗さに優れ、なおかつ被削性が良好であり、更には
黒鉛を析出させるための黒鉛化処理が不要で、安価に製
造することが可能なものを提供することを目的としたも
のであり、その要旨は、重量％で、Ｃ：０．２０〜０．
６０％、Ｓｉ：０．５０〜１．５０％、Ｍｎ：０．１０
〜２．００％、Ｐ：０．０３０％以下、Ｓ：０．０１０
〜０．０７０％、Ａｌ：０．０１５〜０．０６０％、
Ｎ：０．００１０〜０．０１５０％、Ｏ：０．００５０
％以下、Ｃｒ：０．０５〜１．００％、残部がＦｅ及び
不可避的不純物からなり、平均粒径：４．０μｍ以下で
ある黒鉛を有し、さらに組織が主としてフェライトとパ
ーライトと黒鉛からなることを特徴とする仕上げ面粗さ
に優れた快削プラスチック成形金型用鋼にある。SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has excellent finished surface roughness and good machinability. The object of the present invention is to provide a material which does not require a graphitization treatment for precipitating graphite and can be manufactured at a low cost. .
60%, Si: 0.50 to 1.50%, Mn: 0.10
2.00%, P: 0.030% or less, S: 0.010
0.070%, Al: 0.015 to 0.060%,
N: 0.0010 to 0.0150%, O: 0.0050
%, Cr: 0.05 to 1.00%, the balance being Fe and unavoidable impurities, and having graphite having an average particle size of 4.0 μm or less, and further having a structure mainly composed of ferrite, pearlite, and graphite. It is a steel for a free-cutting plastic molding die having an excellent finished surface roughness.
【０００７】[0007]
【発明の実施の形態】以下、本発明を詳細に説明する
に、鋼中のＣに黒鉛化処理を施すことにより黒鉛を析出
させ、この黒鉛を切欠効果，潤滑効果として利用するこ
とで鋼の被削性が向上することは知られているが、現状
の黒鉛析出方法ではその仕上げ面粗さの劣化は免れな
い。その原因としては、切削面の黒鉛が抜け落ちること
によってピット状の穴が出現することと、フェライトー
パーライト粒が粗細混粒組織のために硬さバラツキが大
きくなることが考えられる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Graphite is precipitated by subjecting carbon in steel to a graphitization treatment, and this graphite is used as a notch effect and a lubricating effect. Although it is known that the machinability is improved, the current graphite deposition method is inevitably deteriorated in the finished surface roughness. It is considered that the cause is that pit-like holes appear due to graphite falling off the cut surface, and that the ferrite-pearlite grains have a large hardness variation due to a coarse-grained mixed grain structure.
【０００８】本発明は、上記の原因を除去することによ
り、切削加工における仕上げ面粗さに優れ、且つ安価に
提供できるプラスチック成形金型用鋼の製造方法を提供
しようとするものである。すなわち、上記のような問題
点を改良するため、本発明者等は、積極的にＡｌを適切
量添加してＡｌＮを形成させ、このＡｌＮを微細に析出
させることで黒鉛の析出核を増やし、さらに黒鉛析出温
度域の冷却速度を制御することにより、黒鉛の粗大化を
抑えて均一微細に析出させ、仕上げ面粗さの劣化を防止
することができること、またＡｌＮはオーステナイト結
晶粒の粗大化を抑制して結晶粒径を細かくし、結晶粒径
を細かくすることで硬さバラツキを無くすことができる
こと、を実験の結果知得した。An object of the present invention is to provide a method for producing a steel for a plastic molding die which can be provided at an inexpensive and excellent finished surface roughness in a cutting process by eliminating the above-mentioned causes. That is, in order to improve the above-described problems, the present inventors actively add an appropriate amount of Al to form AlN, and increase the precipitation nuclei of graphite by finely depositing this AlN, Further, by controlling the cooling rate in the graphite precipitation temperature range, it is possible to suppress the coarsening of graphite and to deposit it uniformly and finely, thereby preventing the deterioration of the finished surface roughness.AlN also reduces the austenite crystal grains. Experiments have shown that by suppressing the crystal grain size and reducing the crystal grain size, the hardness variation can be eliminated.
【０００９】本発明は、実験の結果知得した上記技術を
もとに成されたもので、仕上げ面粗さに優れており、ま
た黒鉛を析出させるための黒鉛化処理が不要であり、安
価に供給することが可能な製造方法を開発することがで
きた。以下、これを詳細に説明するに、合金の成分バラ
ンスを限定し、適当量のＡｌを添加してＡｌＮを微細に
析出させることにより黒鉛の析出核を増やし、黒鉛化処
理を行わずとも黒鉛を均一微細に析出させることが可能
である。また、黒鉛析出温度域の冷却速度を制御するこ
とにより、黒鉛が粗大化することを抑えることが可能で
ある。さらに、ＡｌＮはオーステナイト結晶粒の粗大化
を抑制して、結晶粒を細かくすることができる。そし
て、結晶粒を細かくすることで硬さバラツキが無くな
り、仕上げ面粗さが優れたものになる。The present invention is based on the above-mentioned technology obtained as a result of an experiment, has excellent finished surface roughness, does not require graphitization for depositing graphite, and is inexpensive. A manufacturing method that can be supplied to a company was developed. Hereinafter, this will be described in detail by limiting the component balance of the alloy, adding an appropriate amount of Al and precipitating AlN finely to increase the number of graphite precipitation nuclei, and reducing the graphite without graphitization. It is possible to deposit uniformly and finely. Further, by controlling the cooling rate in the graphite deposition temperature range, it is possible to suppress the graphite from becoming coarse. Furthermore, AlN can suppress the coarsening of austenite crystal grains and make the crystal grains fine. And, by making the crystal grains fine, the variation in hardness is eliminated, and the finished surface roughness becomes excellent.
【００１０】つぎに、合金鋼の成分について以下具体的
に説明するに、Ｃの含有量は重量％（以下、同じ）で、
０．２０〜０．６０％とする。Ｃは黒鉛を析出させる上
で不可欠であり、十分な被削性を得るために必要な黒鉛
の量を確保するために、その下限を０．２０％とした。
しかし、Ｃ量が増すと硬くなり、硬いＦｅの炭化物が刃
先を摩滅させるために被削性が劣化するため上限を０．
６０％とした。Next, the components of the alloy steel will be specifically described below. The content of C is expressed as% by weight (hereinafter the same).
0.20 to 0.60%. C is indispensable for depositing graphite, and its lower limit is set to 0.20% in order to secure the amount of graphite necessary for obtaining sufficient machinability.
However, as the C content increases, the steel becomes harder, and the hard carbide of Fe wears the cutting edge, thereby deteriorating the machinability.
60%.
【００１１】また、Ｓｉの含有量は０．５０〜１．５０
％とする。このＳｉは、黒鉛化を促進させる元素の１つ
であり、十分な被削性を得るために必要な黒鉛の量を確
保するために、その下限を０．５０％とした。しかし、
Ｓｉの含有量が多すぎると靭性が劣化するため、上限を
１．５０％とする。そして又、Ｍｎの含有量は０．１０
〜２．００％とする。このＭｎはマトリクスに固溶させ
て強度を確保するためにその下限を０．１０％とする。
多すぎると黒鉛化を阻害するため、上限を２．００％と
した。The content of Si is 0.50 to 1.50.
%. This Si is one of the elements that promote graphitization, and the lower limit is set to 0.50% in order to secure the amount of graphite necessary for obtaining sufficient machinability. But,
If the content of Si is too large, the toughness deteriorates, so the upper limit is made 1.50%. Also, the content of Mn is 0.10
To 2.00%. The lower limit of Mn is set to 0.10% in order to secure the strength by forming a solid solution in the matrix.
If the amount is too large, the graphitization is inhibited, so the upper limit is set to 2.00%.
【００１２】Ｐの含有量は０．０３０％以下とする。こ
のＰは靭性を劣化させ、また黒鉛化を阻害する元素であ
るため、その上限を０．０３０％とした。又、Ｓの含有
量は０．０１０〜０．０７０％の範囲内とする。このＳ
は、ＭｎＳを形成することで直接的に被削性を向上させ
る効果と、黒鉛析出の核となることにより黒鉛析出を促
進させ、被削性を向上させる効果がある。十分な効果を
得るため下限を０．０１０％とした。多すぎると鏡面
性，靭性が劣化するので、その上限を０．０７０％とし
た。The content of P is set to 0.030% or less. Since P is an element that deteriorates toughness and inhibits graphitization, its upper limit is set to 0.030%. Further, the content of S is in the range of 0.010 to 0.070%. This S
Has an effect of directly improving machinability by forming MnS, and an effect of promoting graphite precipitation by being a nucleus of graphite precipitation and improving machinability. The lower limit is set to 0.010% in order to obtain a sufficient effect. If the content is too large, the specularity and toughness deteriorate, so the upper limit was made 0.070%.
【００１３】更に、Ａｌの含有量は０．０１５〜０．０
６０％の範囲内とする。このＡｌはＡｌＮを形成し、オ
ーステナイト結晶粒度を細かくするのに必要である。結
晶粒度を細かくすることで仕上げ面粗さを良好にし、被
削性を改善する。またＡｌＮは、黒鉛の析出核になるこ
とにより黒鉛析出を促進させ、被削性を向上させる効果
がある。この効果を得るためにその下限を０．０１５％
とした。多すぎると酸化物系被金属介在物が増加し、被
削性に悪影響を及ぼすので、その上限を０．０６０％と
する。Further, the content of Al is 0.015 to 0.0
It is within the range of 60%. This Al forms AlN and is necessary to reduce the austenite grain size. By reducing the crystal grain size, the finished surface roughness is improved, and the machinability is improved. In addition, AlN has an effect of promoting graphite precipitation by becoming a graphite precipitation nucleus and improving machinability. To obtain this effect, the lower limit is 0.015%
And If the content is too large, oxide-based metal inclusions increase, which adversely affects the machinability. Therefore, the upper limit is made 0.060%.
【００１４】Ｎの含有量は０．００１０〜０．０１５０
％の範囲内とする。このＮは、ＡｌＮを形成し、オース
テナイト結晶粒度を細かくするのに必要である。結晶粒
度を細かくすることで仕上げ面粗さを良好にし、被削性
を改善する。またＡｌＮは、黒鉛の析出核になることに
より黒鉛析出を促進させ、被削性を向上させる効果があ
る。効果を得るために、その下限を０．００１０％とし
た。多すぎると仕上げ面粗さを劣化するため、その上限
を０．０１５０％とした。The content of N is 0.0010 to 0.0150.
%. This N is necessary to form AlN and reduce the austenite grain size. By reducing the crystal grain size, the finished surface roughness is improved, and the machinability is improved. In addition, AlN has an effect of promoting graphite precipitation by becoming a graphite precipitation nucleus and improving machinability. In order to obtain the effect, the lower limit was made 0.0010%. If the amount is too large, the finished surface roughness deteriorates, so the upper limit was made 0.0150%.
【００１５】また、Ｏの含有量は０．００５０％以下と
する。Ｏは、過度の添加は酸化物系介在物を増加させ、
被削性に悪影響を及ぼすので極力低減することが望まし
く、その上限を０．００５０％とした。更に、Ｃｕの含
有量は０．２０〜１．００％の範囲内とする。Ｃｕは黒
鉛化を促進すると同時に、黒鉛を微細化させる働きがあ
る。またＣｕを添加することにより耐食性が向上する。
しかし０．２０％未満では添加効果が乏しく、また１．
００％を越えて添加すると効果が飽和に達するので、範
囲を０．２０〜１．００％とした。The content of O is set to 0.0050% or less. O, excessive addition increases oxide inclusions,
Since the machinability is adversely affected, it is desirable to reduce as much as possible, and the upper limit is made 0.0050%. Further, the Cu content is in the range of 0.20 to 1.00%. Cu promotes graphitization and has the function of miniaturizing graphite. In addition, the corrosion resistance is improved by adding Cu.
However, if it is less than 0.20%, the effect of addition is poor.
If the addition exceeds 00%, the effect reaches saturation, so the range is 0.20 to 1.00%.
【００１６】更にまた、Ｃｒの含有量を０．０５〜１．
００％の範囲内とする。このＣｒは鋼の焼入性を向上さ
せるのに有効な元素であり、より強度を必要とする場合
に用いる。０．０５％未満では効果が少ないので下限を
０．０５％とする。しかし、Ｃｒは黒鉛析出を阻害する
元素でもあるため、多量の添加は望ましくなく、その上
限を１．００％とする。Further, the content of Cr is set to 0.05 to 1.
Within the range of 00%. This Cr is an element effective for improving the hardenability of steel, and is used when more strength is required. If it is less than 0.05%, the effect is small, so the lower limit is made 0.05%. However, since Cr is also an element that inhibits graphite precipitation, it is not desirable to add a large amount of Cr, and the upper limit is made 1.00%.
【００１７】[0017]
【実施例】表１に、試供材の化学組成及び析出した黒鉛
の平均粒径と面積率を示す。試供材は通常の製鋼法で溶
製し、鍛練比４以上で鍛造したものを放冷した。更に８
００〜９００℃で焼きならし処理を行い、その後５５０
〜６５０℃で焼戻し処理を施した。上記処理で得られた
試供材の硬さはＨＢ１８３〜２４１であった。黒鉛粒径
の測定はＳＥＭを用い５０００倍で１０視野観察し、総
視野面積２５２０μｍ２で実施した。本発明鋼（Ｎ０．
１〜Ｎ０．９）の黒鉛粒径は比較鋼（Ｎ０．１０〜Ｎ
０．２０）のそれよりいずれも小さい。EXAMPLES Table 1 shows the chemical composition of the test material and the average particle size and area ratio of the precipitated graphite. The test material was melted by a normal steelmaking method, and forged at a forging ratio of 4 or more, and allowed to cool. 8 more
A normalizing process is performed at 00 to 900 ° C., and then 550
Tempering treatment was performed at ６650 ° C. The hardness of the test sample obtained by the above treatment was HB183 to 241. The measurement of the graphite particle size was carried out by observing 10 visual fields at a magnification of 5000 using SEM and a total visual field area of 2520 μm 2 . The steel of the present invention (N0.
1 to N0.9) of the comparative steel (N0.10 to N0.9)
0.20).
【００１８】[0018]
【表 １】 [Table 1]
【００１９】表２に、本発明鋼（Ｎ０．１〜Ｎ０．９）
と、比較鋼（Ｎ０．１０〜Ｎ０．２０）の仕上げ面粗さ
（最大粗さＲｙ）、結晶粒度、硬さ測定結果、およびエ
ンドミルによる被削性評価結果を示す。仕上げ面粗さは
触針式の粗さ測定器により測定した。また、結晶粒度の
測定は、ナイタルで腐食させた後、光学顕微鏡により測
定した。また、被削性評価は、２枚刃のエンドミルで側
面切削を行い、工具の境界部の摩耗量（短刃と長刃の平
均）が２００μｍとなるときの加工長さで判断する。被
削性試験は切り込み量：１５ｍｍ、切削幅：１ｍｍ、切
削速度：２１ｍ／ｍｉｎ、送り速度：９４ｍｍ／ｍｉ
ｎ、回転数：６７０ｒｐｍ、１刃当たりの送り量：０．
０７０ｍｍ／刃で実施した。Table 2 shows the steels of the present invention (N0.1-N0.9).
And the finished surface roughness (maximum roughness Ry), the crystal grain size, the hardness measurement result, and the machinability evaluation result by the end mill of the comparative steel (N0.10 to N0.20). The finished surface roughness was measured by a stylus type roughness measuring instrument. The crystal grain size was measured with an optical microscope after corrosion with nital. In addition, the machinability evaluation is performed by performing side cutting with a two-flute end mill and determining the processing length when the amount of wear (average of the short blade and the long blade) at the boundary of the tool is 200 μm. In the machinability test, the cutting depth: 15 mm, the cutting width: 1 mm, the cutting speed: 21 m / min, the feed speed: 94 mm / mi
n, number of revolutions: 670 rpm, feed amount per blade: 0.
The test was performed at 070 mm / blade.
【００２０】[0020]
【表 ２】 [Table 2]
【００２１】図１に、仕上げ面粗さと添加したＡｌ量の
関係を、図２に、結晶粒度と添加したＡｌ量の関係を示
した。Ａｌ添加量が０．０１５〜０．０６０％の時が結
晶粒度が細かく、仕上げ面粗さも良好である。Ａｌ添加
量が微量な場合には仕上げ面粗さはばらつき、良好な仕
上面が得られない。またＡｌ添加量が０．０６０％を越
えると仕上げ面粗さは劣化する。FIG. 1 shows the relationship between the finished surface roughness and the added amount of Al, and FIG. 2 shows the relationship between the crystal grain size and the added amount of Al. When the amount of Al added is 0.015 to 0.060%, the crystal grain size is fine and the finished surface roughness is good. When the amount of Al added is small, the finished surface roughness varies, and a good finished surface cannot be obtained. When the amount of Al exceeds 0.060%, the finished surface roughness is deteriorated.
【００２２】本発明鋼（Ｎ０．１〜Ｎ０．９）は仕上げ
面粗さに優れ、尚且つ被削性に良好なプラスチック成形
金型用鋼であり、プラスチック成形金型用の鋼として必
要な材料硬さを備えている。これに対して、比較鋼（Ｎ
０．１０〜Ｎ０．１６）は被削性において発明鋼に劣
り、比較鋼（Ｎ０．１５，Ｎ０．１７，Ｎ０．１９ ，
Ｎ０．２０）は仕上げ面粗さにおいて発明鋼に劣る。The steel of the present invention (N0.1 to N0.9) is a steel for plastic molding dies which has excellent finished surface roughness and good machinability, and is required as steel for plastic molding dies. Material hardness is provided. On the other hand, the comparative steel (N
0.10 to N0.16) are inferior to the inventive steel in machinability, and comparative steels (N0.15, N0.17, N0.19,
N0.20) is inferior to the invention steel in the finished surface roughness.
【００２３】[0023]
【発明の効果】本発明に係る仕上げ面粗さに優れた快削
プラスチック成形金型用鋼は、上記のように、重量％
で、Ｃ：０．２０〜０．６０％、Ｓｉ：０．５０〜１．
５０％、Ｍｎ：０．１０〜２．００％、Ｐ：０．０３０
％以下、Ｓ：０．０１０〜０．０７０％、Ａｌ：０．０
１５〜０．０６０％、Ｎ：０．００１０〜０．０１５０
％、Ｏ：０．００５０％以下、Ｃｒ：０．０５〜１．０
０％、残部がＦｅ及び不可避的不純物からなり、平均粒
径：４．０μｍ以下である黒鉛を有し、さらに組織が主
としてフェライトとパーライトと黒鉛からなる成分バラ
ンスを限定した構成のものであるから、黒鉛析出温度域
の冷却速度を制御することにより、黒鉛が粗大化するこ
とを抑えることが可能である。また、ＡｌＮを微細に析
出することで黒鉛の析出核を増やし、黒鉛化処理を行わ
ずとも黒鉛を均一微細に析出させることが可能である。
そしてまた、Ａｌを添加することによりＡｌＮを形成
し、オーステナイト結晶粒の粗大化を抑制して、結晶粒
を細かくすることができる。更には、結晶粒系を細かく
することで硬さバラツキが無くなり、仕上げ面粗さが優
れたものになる、といった諸効果がある。According to the present invention, the steel for a free-cutting plastic molding die having an excellent finished surface roughness has a weight percentage of
, C: 0.20-0.60%, Si: 0.50-1.
50%, Mn: 0.10 to 2.00%, P: 0.030
%, S: 0.010-0.070%, Al: 0.0
15 to 0.060%, N: 0.0010 to 0.0150
%, O: 0.0050% or less, Cr: 0.05 to 1.0
0%, the balance being Fe and unavoidable impurities, graphite having an average particle size of 4.0 μm or less, and further having a structure in which the composition balance is limited mainly to ferrite, pearlite, and graphite. By controlling the cooling rate in the graphite deposition temperature range, it is possible to suppress the graphite from becoming coarse. Further, by precipitating AlN finely, it is possible to increase the precipitation nuclei of graphite and to deposit graphite uniformly and finely without performing graphitization treatment.
Further, AlN is formed by adding Al, thereby suppressing austenite crystal grains from becoming coarse and making the crystal grains fine. In addition, there are various effects such as the hardness variation being eliminated by making the crystal grain system fine, and the finished surface roughness being excellent.
【図１】仕上げ面粗さと添加したＡｌ量の関係を示す図
である。FIG. 1 is a view showing a relationship between a finished surface roughness and an added amount of Al.
【図２】結晶粒度と添加したＡｌ量の関係を示す図であ
る。FIG. 2 is a diagram showing the relationship between the crystal grain size and the amount of added Al.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C22C 38/00 - 38/60 B29C 33/38 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. 6 , DB name) C22C 38/00-38/60 B29C 33/38
Claims (2)
Ｓｉ：０．５０〜１．５０％、Ｍｎ：０．１０〜２．０
０％、Ｐ：０．０３０％以下、Ｓ：０．０１０〜０．０
７０％、Ａｌ：０．０１５〜０．０６０％、Ｎ：０．０
０１０〜０．０１５０％、Ｏ：０．００５０％以下、Ｃ
ｒ：０．０５〜１．００％、残部がＦｅ及び不可避的不
純物からなり、平均粒径：４．０μｍ以下である黒鉛を
有し、さらに組織が主としてフェライトとパーライトと
黒鉛からなることを特徴とする仕上げ面粗さに優れた快
削プラスチック成形金型用鋼。1. C .: 0.20 to 0.60% by weight,
Si: 0.50 to 1.50%, Mn: 0.10 to 2.0
0%, P: 0.030% or less, S: 0.010 to 0.0
70%, Al: 0.015 to 0.060%, N: 0.0
010-0.0150%, O: 0.0050% or less, C
r: 0.05 to 1.00%, with the balance being Fe and unavoidable impurities, having an average particle size of graphite having a particle size of 4.0 μm or less, and further comprising a structure mainly composed of ferrite, pearlite, and graphite. Free-cutting plastic molding steel with excellent finished surface roughness.
を含有することを特徴とする請求項１記載の仕上げ面粗
さに優れた快削プラスチック成形金型用鋼。2. Cu: 0.20 to 1.00% by weight
The free-cutting plastic molding die steel according to claim 1, wherein the steel has excellent finished surface roughness.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1638798A JP2934424B2 (en) | 1998-01-12 | 1998-01-12 | Steel for free-cutting plastic molds with excellent finished surface roughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1638798A JP2934424B2 (en) | 1998-01-12 | 1998-01-12 | Steel for free-cutting plastic molds with excellent finished surface roughness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11199966A JPH11199966A (en) | 1999-07-27 |
| JP2934424B2 true JP2934424B2 (en) | 1999-08-16 |
Family
ID=11914863
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1638798A Expired - Fee Related JP2934424B2 (en) | 1998-01-12 | 1998-01-12 | Steel for free-cutting plastic molds with excellent finished surface roughness |
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| Country | Link |
|---|---|
| JP (1) | JP2934424B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4108431A1 (en) * | 2021-06-22 | 2022-12-28 | Mitsubishi Chemical Advanced Materials NV | A method for producing a thermoplastic composite component |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004137521A (en) * | 2002-10-15 | 2004-05-13 | Sanyo Special Steel Co Ltd | Plastic mold steel |
| JP4192579B2 (en) * | 2002-11-29 | 2008-12-10 | 住友金属工業株式会社 | Steel for plastic mold |
-
1998
- 1998-01-12 JP JP1638798A patent/JP2934424B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4108431A1 (en) * | 2021-06-22 | 2022-12-28 | Mitsubishi Chemical Advanced Materials NV | A method for producing a thermoplastic composite component |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH11199966A (en) | 1999-07-27 |
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