JPH0266137A - High-purity steel having superior machineability - Google Patents
High-purity steel having superior machineabilityInfo
- Publication number
- JPH0266137A JPH0266137A JP21947288A JP21947288A JPH0266137A JP H0266137 A JPH0266137 A JP H0266137A JP 21947288 A JP21947288 A JP 21947288A JP 21947288 A JP21947288 A JP 21947288A JP H0266137 A JPH0266137 A JP H0266137A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- less
- purity
- present
- purity steel
- 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.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 116
- 239000010959 steel Substances 0.000 title claims abstract description 116
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 13
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 8
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 229910052717 sulfur Inorganic materials 0.000 abstract description 14
- 229910052802 copper Inorganic materials 0.000 abstract description 7
- 238000000034 method Methods 0.000 abstract description 7
- 229910052760 oxygen Inorganic materials 0.000 abstract description 6
- 229910052718 tin Inorganic materials 0.000 abstract description 5
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 4
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 229910052804 chromium Inorganic materials 0.000 abstract description 3
- 229910052750 molybdenum Inorganic materials 0.000 abstract description 3
- 229910052782 aluminium Inorganic materials 0.000 abstract description 2
- 229910052745 lead Inorganic materials 0.000 abstract description 2
- 229910052748 manganese Inorganic materials 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 abstract description 2
- 229910052758 niobium Inorganic materials 0.000 abstract description 2
- 229910052720 vanadium Inorganic materials 0.000 abstract description 2
- 230000002542 deteriorative effect Effects 0.000 abstract 1
- 229910052759 nickel Inorganic materials 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 12
- 239000000463 material Substances 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 230000001105 regulatory effect Effects 0.000 description 8
- 238000010273 cold forging Methods 0.000 description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000005520 cutting process Methods 0.000 description 5
- 239000010955 niobium Substances 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 230000003749 cleanliness Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 239000002436 steel type Substances 0.000 description 4
- 229910000851 Alloy steel Inorganic materials 0.000 description 3
- 238000005255 carburizing Methods 0.000 description 3
- 239000011651 chromium Substances 0.000 description 3
- 239000011572 manganese Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 230000002195 synergetic effect Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- 229910000997 High-speed steel Inorganic materials 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 238000010791 quenching Methods 0.000 description 2
- 230000000171 quenching effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- 238000009864 tensile test Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910000915 Free machining steel Inorganic materials 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-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
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- QRSFFHRCBYCWBS-UHFFFAOYSA-N [O].[O] Chemical compound [O].[O] QRSFFHRCBYCWBS-UHFFFAOYSA-N 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000010405 reoxidation reaction Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 230000009897 systematic effect Effects 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は主として自動車、建設機械用の各種ギヤー シ
ャフト、ピン類などに使用する優れた温・冷間鍛造性を
もつ、被削性のよい高純度鋼に関する。[Detailed Description of the Invention] (Industrial Application Field) The present invention is mainly used for various gear shafts, pins, etc. for automobiles and construction machinery. Regarding high purity steel.
（従来技術）
わが国の自動車業界では加工コストの低減を目的とじて
Ｓもしくはｐｂを添加した快削鋼を各種の部品に採用し
、一般鋼についても熱間鍛造を温・冷間鍛造に変更する
などの方法により製造工程の合理化を進めてきた。(Prior art) In the Japanese automobile industry, free-cutting steel with S or PB added is used for various parts in order to reduce processing costs, and hot forging is also being changed to warm/cold forging for general steel. We have been streamlining the manufacturing process using methods such as these.
一方、業界ではエンジンの高馬力化にともなう足まわり
部品、駆動系部品の高強度化のニーズから次世代用材料
として真空脱ガスと取鍋精錬法とを絹み合わせ製造した
、とくに靭性の優れた高純度ａｔ＜低Ｐ、Ｓ、Ｃｕ、Ｓ
ｒ、０材料→通常、 Ｐ ０．０１５％以下、Ｓ ０．
０１０％以下、Ｃｕ０．１２％以下、Ｓｎ ０．０１５
％以下、０ ０．００１０％以下に規制された材料を指
す→以下、本文では次世代用高純度鋼と記す）を採用し
始めている。これらの次世代用高純度鋼は、とくに、優
れた温・冷間鍛造性を有し常温近辺での苛酷な塑性加工
に耐える。 （たとえばＳＣＭ４２０鋼の冷間据込試験
においては、割れ発生までの限界据込率は基本鋼の約５
０％からおおよそ１割増しの５６％以上まで改善される
。）しかしながら、以後の切削加工では切りくずが長く
のび工具寿命が劣化するため、被削性の改善が急務とな
っている。On the other hand, in response to the need for higher strength suspension parts and drive system parts in line with the increase in engine horsepower, the industry has developed a next-generation material that combines vacuum degassing and ladle refining methods to produce materials with particularly excellent toughness. High purity at<low P, S, Cu, S
r, 0 material → Normal, P 0.015% or less, S 0.
0.010% or less, Cu 0.12% or less, Sn 0.015
% or less, 0.00% or less (hereinafter referred to as next-generation high-purity steel in the text). These next-generation high-purity steels have particularly excellent hot and cold forgeability and can withstand severe plastic working at near room temperature. (For example, in a cold upsetting test of SCM420 steel, the critical upsetting rate before cracking was approximately 5
It is improved from 0% to more than 56%, which is an increase of approximately 10%. ) However, in subsequent cutting processes, chips are elongated and tool life is deteriorated, so there is an urgent need to improve machinability.
本発明者らは、すでに前記の問題点を解決するものとし
て、 「切りくず処理性のよい高靭性鋼」を開発し特許
出願している（特願昭６１−３１３９９０号）。The present inventors have already developed and filed a patent application for "high toughness steel with good chip control" as a solution to the above-mentioned problems (Japanese Patent Application No. 313990/1982).
この先願鋼は酸素量を１０ｐｐｍ以下の極低値とし、ざ
らにＰ ０．０１５％以下、Ｓ ０．００７％以下、Ａ
ｌ ０．０１５〜０．０５０％、 Ｎ ０．００８
〜０．０２０％とし、Ｐｂ量をｏ、ｏｉｏ〜０．０４０
％に規制したもので、機械的性質は無鉛の真空脱ガスし
た基本鋼と同等以上で、かつ、切りくず処理性（破砕性
）を改善した鋼である。This previously applied steel has an extremely low oxygen content of 10 ppm or less, P 0.015% or less, S 0.007% or less, and A
l 0.015-0.050%, N 0.008
~0.020%, and the amount of Pb is o, oio ~0.040
%, and has mechanical properties equivalent to or better than lead-free vacuum-degassed basic steel, and has improved chip control (crushability).
しかしながらこの鋼の温・冷間鍛造性は前記した次世代
用高純度鋼に求められているレベルに比し不十分であり
、また切りくず処理性は向上したものの、工具寿命はご
く僅かしか改善されなかった。However, the hot and cold forgeability of this steel is insufficient compared to the level required for the above-mentioned next-generation high-purity steels, and although chip control has improved, tool life has only improved slightly. It wasn't done.
（解決すべき課Ｂ）
本発明は上記の問題点を解決するためになされたもので
ありで、機械的性質と温・冷間鍛造性とは次世代用高純
度鋼とほぼ同等、もしくはそれ以上の水準であり、さら
に切りくず処理性とともに工具寿命をも改善した「被削
性のよい高純度鋼」を提供することを目的としている。(Problem to be solved B) The present invention was made to solve the above problems, and the mechanical properties and hot/cold forgeability are almost equivalent to, or even better than, next-generation high-purity steel. The objective is to provide ``high-purity steel with good machinability'' that meets the above standards and also has improved chip control and tool life.
（課題の解決手段）
かかる目的達成のため、本発明者らは次世代用高純度鋼
について種々の改善研究を重ねた結果、高度の高純度鋼
においては、Ｐｆｆｉを極低値の０．０１０％以下とし
、Ｓｉ量を０．１０％以下に規制した上でＰｂを０．０
０５〜０．０４０％添加するとｐｂ添加による靭性、機
械的性質および温・冷間鍛造性の労化が起こらず、同時
に被削性、とくに工具寿命が向上することを低合金鋼中
の各不純物元素量のコントロールと組み合わせた系統的
な調査から見いだし、この効果が各種の実用鋼において
も顕著であることを確かめたことから本発明をなしたも
のである。(Means for Solving the Problem) In order to achieve this objective, the present inventors have conducted various improvement studies on next-generation high-purity steel, and as a result, in advanced high-purity steel, Pffi has been reduced to an extremely low value of 0.010. % or less, and the amount of Si is regulated to 0.10% or less, and Pb is 0.0% or less.
Each impurity in low alloy steel has been shown to improve toughness, mechanical properties, and hot/cold forgeability by adding 0.05% to 0.040%, and at the same time improve machinability, especially tool life. This was discovered through a systematic investigation combined with control of the amount of elements, and the present invention was made based on the fact that this effect was found to be significant in various practical steels.
本願における第一の発明鋼は重量％てＣ０．０７〜ｌ’
、 １０％、 Ｓｉ ０．１０％以下、Ｍｎ０．ＩＯ
〜２．００％、Ｐ ０．０１０％以下、Ｓ ０．００５
％以下、Ｃｕ０．１２％以下、Ｓｎ０．０１５％以下、
Ａｌ０．Ｏ１５〜０．０５０％、Ｎ ０．００８〜０
．０２０％、００．００１０％以下Ｐｂ ０．００５〜
０．０４０％、残部Ｆｅおよび必然的に含まれる不純物
からなる被削性のよい高純度鋼である。The first invention steel in this application has C0.07 to l' in weight%.
, 10%, Si 0.10% or less, Mn0. IO
~2.00%, P 0.010% or less, S 0.005
% or less, Cu 0.12% or less, Sn 0.015% or less,
Al0. O15~0.050%, N0.008~0
．． 020%, 00.0010% or less Pb 0.005~
It is a high-purity steel with good machinability, consisting of 0.040%, the balance Fe and impurities inevitably included.
本ａにおける第二の発明鋼は第一の発明の鋼にＮｉ５．
０Ｑ％以下、Ｃｒ ２． 、 Ｏ０％以下、Ｍｏ １．
００％以下、■０．１０％以下、Ｎｂ ０．０８％以下
の内１種もしくは２種以上を添加し、機械的性質、浸炭
・焼入焼もどしなどの熱処理特性の一層の改善、向上を
はかフた被削性のよい高純度鋼である。本発明鋼は次世
代用高純度鋼と比較してほぼ同等、もしくはそれ以上の
打力持性、とくに優れた温・冷間鍛造性を有し、さらに
切削加工において良好な工具寿命が得られるため、自動
車、建設機械用部品の材料として最適である。なお高純
度鋼とは微量不純物元素の内、とくにＰ、Ｓ、Ｃｕ、Ｓ
ｎ、Ｏ量を従来鋼の水準より著しく低減させ、高純度化
をはかフた鋼という意味で使用した。The second invention steel in this a is the steel of the first invention with Ni5.
0Q% or less, Cr 2. , O0% or less, Mo 1.
00% or less, ■0.10% or less, and Nb 0.08% or less to further improve mechanical properties and heat treatment properties such as carburizing, quenching and tempering. It is a high-purity steel with excellent machinability. Compared to next-generation high-purity steels, the steel of the present invention has almost the same or better striking force retention, particularly excellent hot and cold forgeability, and also has good tool life during cutting. It is ideal as a material for parts for automobiles and construction machinery. Furthermore, high-purity steel does not contain trace impurity elements, especially P, S, Cu, and S.
The content of n and 0 was significantly reduced compared to the level of conventional steel, and it was used in the sense of a high-purity steel.
次世代用高純度鋼では通常、Ｐを０．０１５％以下、Ｓ
を０．０１０％以下に規制しているが本発明鋼ではＰｆ
ｆｉをさらに極低値の０．０１０％以下とし、加えて、
Ｓｊｌを０．００５％以下、Ｓｉ量を０．１０％以下に
規制した上でＰｂを０．００５〜０．０４０％添加して
いるため、主として低Ｓｔ、低Ｐ、低Ｓ化の相乗効果に
より、次世代用高純度鋼とほぼ同等、もしくはそれ以上
の優れた温・冷間鍛造性が得られる。さらに、とくに低
Ｐ化とＰｌ）添加との相乗効果により工具寿命が基本鋼
く非鉛鋼）より改善される。 （ただし、Ｐｂ単独での
工具寿命の改善度はごく僅かしかない）添加されるＰｂ
量は一般の鉛快削鋼の０６１０〜０．３０％に比し、ｌ
／７以下の０．００５〜０．０４０％と低いため靭性の
低下がなく、しかも切りくずの処理性は基本鋼（非鉛鋼
）に比し向上する。For next-generation high-purity steel, P is usually 0.015% or less and S
Pf is regulated to 0.010% or less, but in the steel of the present invention, Pf
fi is further set to an extremely low value of 0.010% or less, and in addition,
Since Sjl is regulated to 0.005% or less and Si content is regulated to 0.10% or less, and Pb is added at 0.005 to 0.040%, synergistic effects of low St, low P, and low S are achieved. As a result, excellent hot and cold forging properties can be obtained that are almost equal to or better than next-generation high-purity steels. Furthermore, the tool life is improved compared to basic steel (lead-free steel) due to the synergistic effect of the lower P content and the addition of Pl. (However, the degree of improvement in tool life with Pb alone is very small) Added Pb
The amount is l
Since the content is as low as 0.005 to 0.040%, which is less than /7, there is no deterioration in toughness, and the chip disposability is improved compared to basic steel (non-lead steel).
（作 用）
次に、本発明鋼の成分範囲を前述のごとく限定した理由
を以下に述べる。(Function) Next, the reason for limiting the composition range of the steel of the present invention as described above will be described below.
なお、特にことわりがない限り、本明細書において［％
］は重量％である。In addition, unless otherwise specified, in this specification, [%
] is weight %.
Ｃ（炭素）
自動車、建設機械の各種ギヤー シャフト、ビン類には
、浸炭、浸炭窒化もしくは焼入焼もどじした炭素鋼・低
合金鋼が用いられている。浸炭鋼のＣ量下限は０．０７
％、焼入焼もどし用鋼の実用的なＣｆＩｋの上限は１．
１０％であることから、本発明鋼のＣ量については、−
「限を０．０７％とし、上限を１．１０％とする。C (Carbon) Carburized, carbonitrided, or quenched and hardened carbon steel and low-alloy steel are used for various gear shafts and bottles in automobiles and construction machinery. The lower limit of C content in carburized steel is 0.07
%, the practical upper limit of CfIk for quenched and tempered steel is 1.
Since it is 10%, the amount of C in the steel of the present invention is -
“The limit shall be 0.07% and the upper limit shall be 1.10%.
Ｓｉ（ケイ素）
鋼中のＳｌは固溶強化および焼もどし軟化抵抗性の向上
に有効であり焼入れ性、打力を向上さぜるため通常鋼で
はＳｌを０．２０〜０．３０％添加している。しかしな
がら、本発明の高純度鋼中の５１はフェライトを硬化し
、とくに温・冷間鍛造性を低下させ被削性を劣化させる
ので、できる限り低値とすることが望ましい。Si (Silicon) Sl in steel is effective for solid solution strengthening and improving resistance to temper softening. In order to improve hardenability and striking force, 0.20 to 0.30% of Sl is added to ordinary steel. ing. However, since 51 in the high-purity steel of the present invention hardens ferrite, particularly reduces hot and cold forgeability and deteriorates machinability, it is desirable to keep the value as low as possible.
しかし、Ｓｉの低減は製鋼コストの著しい上昇をもたら
すことから経済性を考慮し、上限を０．１０％とする。However, since reducing Si brings about a significant increase in steel manufacturing costs, the upper limit is set at 0.10% in consideration of economic efficiency.
Ｍｎ（マンガン）
鋼中のＭｎは焼入性の調整に大きな役割を有し、とくに
炭素鋼・低合金鋼の焼入性の向上には廉価なこともあっ
て好んで用いられている。添加効果は一般に、また本発
明鋼においても０．１０％以上で顕著となり２．００％
を越えると小さくなるため下限を０．１０％とし、上限
を２．００％とした。Mn (manganese) Mn in steel plays a major role in adjusting the hardenability, and is particularly preferred for improving the hardenability of carbon steel and low alloy steel because it is inexpensive. The effect of addition is generally noticeable at 0.10% or more, and also in the steel of the present invention, and becomes noticeable at 2.00% or more.
If it exceeds this, it becomes small, so the lower limit was set to 0.10% and the upper limit was set to 2.00%.
Ｐ （リン）
鋼中のＰは靭性を減じ冷鍛性を劣化さぜる有害な元素で
ありｐｍはできる限り低い方が望ましい。それゆえ、次
世代用高純度鋼では通常、Ｐｆｌを０．０１５％以下に
規制している。P (Phosphorus) P in steel is a harmful element that reduces toughness and deteriorates cold forgeability, and it is desirable that pm be as low as possible. Therefore, in next-generation high-purity steels, Pfl is usually regulated to 0.015% or less.
本発明鋼においては、Ｐをさらに極低値の０．０１０％
以下とし、加えて、Ｓｉ量を０．１０％以下に規制した
上でＰｂを０．００５〜０．０４０％添加すると、各元
累とくにｐｂとの相乗効果によりハイス工具によるドリ
ル穿孔性、旋削工具寿命が改善される。Ｐ量低減による
ハイス工具寿命の延長と温・冷間鍛造性の改善効果は０
．０１０％以下で顕著となるため、Ｐ低減による製鋼コ
ストの上昇をも考慮して、上限を０．０１０％とする。In the steel of the present invention, P is further added to an extremely low value of 0.010%.
In addition, by controlling the amount of Si to 0.10% or less and adding 0.005 to 0.040% of Pb, the synergistic effect of each element, especially with PB, improves drilling performance with high-speed steel tools. Tool life is improved. The effect of extending the life of high-speed steel tools and improving hot and cold forging properties by reducing the amount of P is 0.
．． Since this becomes noticeable at 0.010% or less, the upper limit is set to 0.010%, taking into account the increase in steel manufacturing costs due to P reduction.
Ｓ （イオウ）
鋼中のＳは主としてＭｎＳ系硫化物、もしくはこれと酸
化物との複合体の形で存在し、鋼の被削性を向上させる
が靭性を著しく低下させ、とくに温・冷鍛性を劣化させ
る。それゆえ、本発明鋼においては機械的性質の向上に
主点をおき、上限を０．００５％とする。S (Sulfur) S in steel mainly exists in the form of MnS-based sulfides or complexes of this and oxides, and although it improves the machinability of steel, it significantly reduces toughness, especially when hot or cold forged. degrade sexuality. Therefore, in the steel of the present invention, the main point is to improve the mechanical properties, and the upper limit is set to 0.005%.
Ｃｕ（！ｉり
鋼中のＣｕはＰと同様に靭性を減じ、温間および冷間加
工性を阻害するためＣｕ量はてきる限り低値とする必要
がある。それゆえ、一般に、また次世代用高純度鋼にお
いても、後述するＳｎと併せＣｕ量を０．１５％以下に
規制している。Cu (!) Like P, Cu in steel reduces toughness and inhibits warm and cold workability, so the amount of Cu must be kept as low as possible. Even in generation-grade high-purity steel, the amount of Cu is regulated to 0.15% or less, together with Sn, which will be described later.
しかしながら、Ｃｕそのものは電炉精錬では除去が困難
で溶解材料を厳選するしかない。それゆえ、本発明鋼に
おいても材料コストの上昇を考慮し、上限を０．１２％
とする。However, Cu itself is difficult to remove by electric furnace refining, so the melting material must be carefully selected. Therefore, in consideration of the increase in material cost, the upper limit was set at 0.12% for the steel of the present invention.
shall be.
Ｓｎ（スズ）
鋼中のＳｎはＰｂと同様に靭性を減じ、有害な元素であ
る。Ｓｎ量はできる限り低値とすべきである。次世代用
高純度鋼でもＳｒｒ量を０．０１５％以下に規制してい
る。溶鋼の脱ガス処理ととりべ精錬法との組み合わせ、
および溶解材料の厳選によって一般に、また本発明鋼に
おいても０．０１５％までの低減は十分に可能である６
Ｓｎ低減に要する精錬コストの上昇をも考慮して上限を
０．０１５％とする。Sn (Tin) Like Pb, Sn in steel reduces toughness and is a harmful element. The amount of Sn should be as low as possible. Even in next-generation high-purity steel, the Srr content is regulated to 0.015% or less. Combination of molten steel degassing treatment and ladle refining method,
In general, and also in the steel of the present invention, reductions to 0.015% are fully possible by carefully selecting melting materials6.
The upper limit is set to 0.015% in consideration of the increase in refining cost required to reduce Sn.
Ａｌ（アルミニウム）
Ａ１は酸素レベルの調整、硫化物の析出形態、結晶粒度
の調整に効果的に作用する。Al (aluminum) A1 effectively acts to adjust the oxygen level, the precipitation form of sulfide, and the crystal grain size.
かような効果は一般に、また本発明鋼においても、０．
０１５％から顕著になる。また、Ａｌを大量添加すると
溶鋼の再酸化、鋼塊内の偏析、結晶粒度の粗大化が起こ
る。それゆえ、下限を０．０１５％、上限を０．０５０
％とした。Such an effect generally exists, and also in the steel of the present invention.
It becomes noticeable from 0.015%. Furthermore, when a large amount of Al is added, reoxidation of molten steel, segregation within the steel ingot, and coarsening of grain size occur. Therefore, the lower limit is 0.015% and the upper limit is 0.050.
%.
Ｎ（窒素）
鋼中に含まれるＮは主としてＡｌＮの形で存在し、結晶
粒の微細化に効果を発揮する。N (Nitrogen) N contained in steel mainly exists in the form of AlN and is effective in refining crystal grains.
この効果は一般に、また本発明鋼においても、０．００
８％以上で顕著となり、０ 、０２０％以上では飽和す
るため下限をｏ、ｏｏｓ％、上限を０．０２０％とした
。This effect generally and also in the steel of the present invention is 0.00
It becomes noticeable at 8% or more, and saturates at 0.020% or more, so the lower limit was set to 0.00% and the upper limit was set to 0.020%.
０（酸素）
鋼中の酸素は酸化物の形で存在し、鋼の機械的性質に有
害であり極低値とする必要がある。とくに冷・温鍛性、
疲労特性に有害な酸化物量を激減するには一般に、また
本発明鋼においても、酸素量を０．００１０％以下とし
なければならない。このような極低水準でないと次世代
用高純度鋼材料と同等、もしくはそれ以上の優れた機械
的性質をひき出せない。それゆえ上限を０゜００１０％
とする。0 (Oxygen) Oxygen in steel exists in the form of oxides and is harmful to the mechanical properties of steel, so it must be kept at an extremely low value. Especially cold and hot forging properties,
In order to drastically reduce the amount of oxides harmful to fatigue properties, generally, and also in the steel of the present invention, the amount of oxygen must be 0.0010% or less. Unless it is at such an extremely low level, it will not be possible to derive mechanical properties that are equivalent to or better than next-generation high-purity steel materials. Therefore, the upper limit is 0゜0010%
shall be.
Ｐｂ（鉛）
一般に、鋼にＰｂを０．１０〜０．３０％添加すると鋼
中に生成してくる鉛粒の切削時の切欠き効果と潤滑作用
により切削砥抗が減少し、切りくずの破砕性、工具寿命
が改善されることはよく知られている。本発明の高純度
鋼ではＰを０．０１０％以下の極低値とし、さらに低ｓ
ｉ、低Ｓ化したことにより、この効果が０．００５％か
ら顕著にあられれるので下限を０．００５％とする。Pb (Lead) Generally, when 0.10 to 0.30% of Pb is added to steel, the cutting force is reduced due to the notch effect and lubrication effect of the lead grains generated in the steel, and the chip formation is reduced. It is well known that friability and tool life are improved. In the high-purity steel of the present invention, P is set to an extremely low value of 0.010% or less, and the s
i. By lowering the S content, this effect becomes noticeable from 0.005%, so the lower limit is set to 0.005%.
一方、ｐｂ量が０．０４Ｃｌ％を越えると、機械的性質
とくに転勤疲労特性の劣化が著しくなるので上限を０．
０４０％とした。On the other hand, if the amount of PB exceeds 0.04Cl%, the deterioration of mechanical properties, especially transfer fatigue properties, becomes significant, so the upper limit should be set to 0.04Cl%.
040%.
Ｎｉにッケル）
鋼にＮｉを添加する目的は必要な焼入性を与え、焼入焼
もどし後の機械的性質を向上させるためである。本発明
鋼で焼入性、優れた機械的性質を必要とする場合にＮｉ
を添加する。The purpose of adding Ni to steel is to provide necessary hardenability and improve mechanical properties after quenching and tempering. When hardenability and excellent mechanical properties are required for the steel of the present invention, Ni
Add.
しかし、ＮｉＪが５％をこえると、残留オーステナイト
が過剰となって表面カタサが低下し、自動車部品に必要
な規格カタサを満たすことが困難となる。それゆえ、上
限を５．００％とした。However, when NiJ exceeds 5%, residual austenite becomes excessive and the surface roughness decreases, making it difficult to meet the standard roughness required for automobile parts. Therefore, the upper limit was set at 5.00%.
Ｃｒ（クロム）
鋼にＣ「を添加する目的は一般に、また本発明鋼におい
ても、必要な焼入性をあたえ浸炭などの熱処理作業を容
易にするためである。Cr (Chromium) The purpose of adding C to steel generally, and also to the steel of the present invention, is to provide necessary hardenability and facilitate heat treatment such as carburizing.
しかし、２，００％を越えると浸炭時に複炭化物を形成
し、反対に焼入性が悪くなる。それゆえ上限を２．００
％とした。However, if it exceeds 2,00%, double carbides are formed during carburizing, and hardenability deteriorates. Therefore, the upper limit is 2.00
%.
Ｍｏ（モリブデン）
鋼にＭｏを添加する目的は一般に、また本発明鋼におい
ても、必要な焼入性をｉテえ、機械的性質を改善するこ
とにある。Mo (Molybdenum) The purpose of adding Mo to steel generally, and also to the steel of the present invention, is to maintain the necessary hardenability and improve mechanical properties.
しかし、１％をこえると、Ｃｒと同じく反対（こ煩人件
が悪くなる。それゆ太、上限を１．００％とした。However, if it exceeds 1%, the upper limit is set at 1.00%.
■（バナジウム）
■は鋼中に溶けこみフェライトを強化するとともに結晶
粒を微細化し、その粒成長を抑制して合金元素の特性を
高める。結晶粒度の微細化におよぼすＶの効果は一般に
、また本発明鋼においても、０．１０％をこえるとほと
んど飽和するので、添加効果と経済性の面から上限を０
９１０％とした。■(Vanadium) ■ dissolves into the steel, strengthens the ferrite, refines the crystal grains, suppresses grain growth, and improves the properties of the alloying element. Generally, the effect of V on grain refinement is almost saturated when it exceeds 0.10%, even in the steel of the present invention.
It was set at 910%.
Ｎｂ（ニオブ）
Ｎｂは鋼中の炭素、窒素などと結びつき細かい析出物と
なって結晶粒を微細化するとともに常温、高温における
強さを増加する。結晶粒度の微細化におよぼすＮｂの効
果は一般に、また本発明鋼においても、０．０８％をこ
えるとほとんど飽和するので、添加効果と経済性の面か
ら上限を０．０８％とした。Nb (Niobium) Nb combines with carbon, nitrogen, etc. in steel to form fine precipitates that refine crystal grains and increase strength at room and high temperatures. Generally, the effect of Nb on grain refinement is almost saturated when it exceeds 0.08%, even in the steel of the present invention, so the upper limit was set at 0.08% from the viewpoint of addition effect and economical efficiency.
（実施例）
つぎに、実施例によって本発明をさらに説明する。基本
鋼種はＳＣＭ４２０，５Ｃｒ４２０，５Ｃｒ４４０゜５
３５Ｃ，５５３Ｃ，ＳＭｎ４４３，５ＡＥ２３３０，５
ＡＥ４０６３，５ＮＣ６３１゜５ＡＥ４６２０．ＳＮＣ
Ｍ４２０．ＳＮＣＭ８１５．および５ＵＪ２の１３種類
とした。各鋼種を真空誘導炉で溶製して得られた１００
ｋｇ鋼塊をφ６５ｍｍに鍛伸し以後の調査に供した。(Examples) Next, the present invention will be further explained by examples. Basic steel types are SCM420, 5Cr420, 5Cr440°5
35C, 553C, SMn443, 5AE2330, 5
AE4063,5NC631゜5AE4620. SNC
M420. SNCM815. and 5UJ2. 100 obtained by melting each steel type in a vacuum induction furnace
kg steel ingot was forged and drawn to a diameter of 65 mm and used for subsequent investigation.
第１表に試験した発明鋼（Ｎｏ、Ａｌ〜Ａ２１）、比較
鋼（ＮＯ０旧〜８９．Ｈ１ｌ〜Ｈ１４）および従来鋼（
Ｈｌｏ、旧５〜＋１２６）合計４７ヒートの化学成分（
重量％）を示す。ここに示す比較鋼（ＳＣＭ４２０．５
Ｃｒ４２０相当鋼）はＰ、Ｓｉ、Ｐｂ、５ｆｉｔが特許
請求範囲を外れている。従来鋼は先に述べた次世代用高
純度鋼である。Table 1 shows the tested invention steels (No. Al to A21), comparative steels (NO0 old to 89.H1l to H14), and conventional steels (No.
Hlo, former 5~+126) total of 47 heat chemical components (
weight%). Comparative steel shown here (SCM420.5
Cr420 equivalent steel) P, Si, Pb, and 5fit are outside the scope of claims. Conventional steel is the next-generation high-purity steel mentioned above.
第２表にはφ６５ｍｍ鍛伸材につき非金属介在物の清浄
度をＪＩＳ Ｇ ０５５５に定められている点算法で測
定した結果を示す。発明鋼、比較鋼および従来鋼の清浄
度は非常に高く、とくに発明鋼のＡ、Ｂ、Ｃ系介在物の
清浄度は一部の鋼を除きゼロとなった。これはＳ量が０
．００５％以下となり、酸素量も０．００１０％以下に
コントロールされたためである。同表中には抗張力、伸
び、紋り、衝撃値、回転曲げ疲労強度をも示した。発明
鋼では、伸び、紋り、衝撃値（Ｔ。Table 2 shows the results of measuring the cleanliness of non-metallic inclusions on φ65 mm forged materials using the point counting method specified in JIS G 0555. The cleanliness of the invention steel, comparative steel, and conventional steel was very high, and in particular, the cleanliness of A, B, and C-based inclusions in the invention steel was zero except for some steels. This means that the amount of S is 0.
．． This is because the oxygen content was controlled to be 0.005% or less, and the oxygen amount was also controlled to 0.0010% or less. The same table also shows tensile strength, elongation, scratches, impact value, and rotating bending fatigue strength. The invented steel has elongation, warpage, and impact value (T.
し方向、Ｔ／Ｌ）疲労強度（σＩＪＬ）、疲労比共に比
較鋼より向上し、次世代用高純度鋼と同等、もしくはそ
れ以上の機械的性質を有することがわかる。発明鋼が比
較鋼より良好な機械的性質を示す理由は十分に明らかで
はないが鋼中の不純物元素ｆｌｋ （Ｐ、Ｓ、Ｃｕ、Ｓ
ｎ）を極低値とし、非金属介在物の清浄度を著しく改善
したためと考えられる。It can be seen that both the fatigue strength (σIJL) and the fatigue ratio in the direction (T/L) and the fatigue ratio are improved compared to the comparative steel, and that it has mechanical properties equivalent to or better than next-generation high-purity steel. The reason why the invented steel exhibits better mechanical properties than the comparative steel is not fully clear, but impurity elements flk (P, S, Cu, S
This is thought to be due to the extremely low value of n), which significantly improved the cleanliness of nonmetallic inclusions.
第３表には冷鍛実験および６００℃での高温引張試験結
果を示した。冷鍛実験ではφ１４ｍｍＸ２１ｍｍ高さの
ミゾ付き試験片（日本波性加工学会、冷鍛分科会２号試
験片）を冷間で据込加工し、ミゾ部に割れが発生する高
さを測定後次式により限界掘込率を算出した。Table 3 shows the results of the cold forging experiment and the high temperature tensile test at 600°C. In the cold forging experiment, a test piece with grooves of φ14 mm x 21 mm height (Japanese Corrugation Society, Cold Forging Subcommittee No. 2 test piece) was cold-upset, and the height at which cracks occur in the groove was measured. The critical digging rate was calculated using the formula.
限界据込率（％）＝
（（２１−割れ発生高さｍｍ） ／ ２１） Ｘ １０
０発明鋼の限界据込率はいずれの鋼種でも比較鋼および
従来鋼のそれより大きく、優れた冷間加工性を有するこ
とがわかる。これは、発明鋼中のＳ、０ｆｆｉを極低値
としてＡ、１３．Ｃ系介在物量をほとんどゼロと、し、
ざらにＰ、Ｓｉ量を規制して加工硬化度を゛改６．善す
ることにより割れの１ｂ。Limit upsetting rate (%) = ((21-crack occurrence height mm) / 21) X 10
It can be seen that the critical upsetting rate of the invention steel is greater than that of the comparison steel and conventional steel for all steel types, indicating that it has excellent cold workability. This is A, 13. with S and Offi in the invention steel being set to extremely low values. The amount of C-based inclusions is reduced to almost zero,
Roughly regulating the amounts of P and Si to improve the degree of work hardening 6. 1b of cracking by improving.
発生が抑制されるためと考えられる。This is thought to be because the outbreak is suppressed.
６００℃での高温引張試験でも発明鋼は比較鋼および従
来鋼に比し、高い伸び、紋り値を示し、前記した優れた
加工性が温間領域にいたるまで保持されることがわかる
。Even in a high-temperature tensile test at 600° C., the invented steel showed higher elongation and scratch values than the comparative steel and conventional steel, indicating that the above-mentioned excellent workability is maintained up to the warm range.
第４表にはドリル試験およびハイス工具寿命試験結果を
示した。発明鋼はいずれの鋼種についても、当然のこと
ながら、比較鋼より優れた被削性を示すことがわかる。Table 4 shows the results of the drill test and the HSS tool life test. It can be seen that the invention steel exhibits better machinability than the comparative steel for all steel types.
低Ｓｉ 、Ｐ、Ｓ化とごく少量のＰｂ添加の組み合せに
よって工具寿命が比較鋼より改善される理由は明らかで
はないが、低Ｓｉ化によって切削抵抗が減少し、ざらに
低Ｐ化によって工具表面に構成刃先が生成し、これが保
Ｗ１層として作用し工具寿命が改善されるものと考えら
れる。It is not clear why the combination of low Si, P, and S and the addition of a very small amount of Pb improves tool life compared to comparative steels, but low Si reduces cutting force, and low P roughly improves the tool surface. It is thought that a built-up cutting edge is formed on the surface, which acts as a W1 layer and improves the tool life.
以上・ 詳述したように、本発明鋼は清？′ＩＩ度、抗
張力、伸び、紋り、衝撃値、回転曲げ疲労、温・冷鍛性
などは次世代用高純度鋼と同等、もしくはそれ以上であ
って、切屑処理性が良く、とくに工具寿命が低Ｐｂ （
０，０４％以下）にもかかわらず向上することがわかる
。As detailed above, is the steel of the present invention clean? 'II degree, tensile strength, elongation, scratches, impact value, rotary bending fatigue, hot/cold forging properties, etc. are equivalent to or better than next-generation high-purity steels, and chip control is good, especially for tool life. is low Pb (
0.04% or less).
（発明の効果）
本発明の被削性のよい高純度鋼を自動車、建設機械用の
各種ギヤー、シャフト、ピン類などに使用すると、現用
材にくらべて部品の軽量化、温・冷鍛形状の複雑化に対
応でき、被削性の改善をはかることが可能となり、高強
度化と加工性の改善の相反するニーズを満足させ、同時
に工程費用をも低減できる。(Effects of the invention) When the high-purity steel with good machinability of the present invention is used for various gears, shafts, pins, etc. for automobiles and construction machinery, the parts can be made lighter and have hot and cold forged shapes compared to current materials. It is possible to cope with the increasing complexity of the process, improve machinability, satisfy the conflicting needs of higher strength and improve workability, and reduce process costs at the same time.
Claims (2)
のよい高純度鋼。(1) By weight: C 0.07-1.10% Si 0.10% or less Mn 0.10-2.00% P 0.010% or less S 0.005% or less Cu 0.12% or less Sn 0.015% or less Al 0.015 ~0.050% N0.008~0.020% O0.0010% or less Pb0.005~0.040% High purity steel with good machinability, consisting of the balance Fe and inevitably contained impurities.
然的に含まれる不純物からなる被削性のよい高純度鋼。(2) C0.07-1.10% Si 0.10% or less Mn 0.10-2.00% P 0.010% or less S 0.005% or less Cu 0.12% or less Sn 0.015% or less Al 0.015 ~0.050% N0.008~0.020% O0.0010% or less Pb0.005~0.040% Furthermore, Ni5.00% or less Cr2.00% or less Mo1.00% or lessV0.10% or less and Nb0. High purity steel with good machinability, containing one or more of 0.08% or less, with the balance being Fe and inevitably contained impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21947288A JPH0266137A (en) | 1988-08-31 | 1988-08-31 | High-purity steel having superior machineability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21947288A JPH0266137A (en) | 1988-08-31 | 1988-08-31 | High-purity steel having superior machineability |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0266137A true JPH0266137A (en) | 1990-03-06 |
Family
ID=16735966
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21947288A Pending JPH0266137A (en) | 1988-08-31 | 1988-08-31 | High-purity steel having superior machineability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0266137A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1041166A1 (en) * | 1999-03-30 | 2000-10-04 | Fujikiko Kabushiki Kaisha | Steel for gear, drive plate gear, and method for producing the drive plate gear |
| JP2013036096A (en) * | 2011-08-09 | 2013-02-21 | Sanyo Special Steel Co Ltd | Steel for machine structure excellent in toughness |
| JP2019035126A (en) * | 2017-08-18 | 2019-03-07 | 大同特殊鋼株式会社 | Steel for machine structure use |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59126718A (en) * | 1983-01-07 | 1984-07-21 | Daido Steel Co Ltd | Manufacture of stel material with superior cold workability |
| JPS6223929A (en) * | 1985-07-22 | 1987-01-31 | Daido Steel Co Ltd | Manufacture of steel for cold forging |
| JPS63162842A (en) * | 1986-12-25 | 1988-07-06 | Sanyo Tokushu Seiko Kk | High toughness steel with satisfactory treatment of chip |
-
1988
- 1988-08-31 JP JP21947288A patent/JPH0266137A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59126718A (en) * | 1983-01-07 | 1984-07-21 | Daido Steel Co Ltd | Manufacture of stel material with superior cold workability |
| JPS6223929A (en) * | 1985-07-22 | 1987-01-31 | Daido Steel Co Ltd | Manufacture of steel for cold forging |
| JPS63162842A (en) * | 1986-12-25 | 1988-07-06 | Sanyo Tokushu Seiko Kk | High toughness steel with satisfactory treatment of chip |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1041166A1 (en) * | 1999-03-30 | 2000-10-04 | Fujikiko Kabushiki Kaisha | Steel for gear, drive plate gear, and method for producing the drive plate gear |
| US6330836B1 (en) | 1999-03-30 | 2001-12-18 | Fujikiko Kabushiki Kaisha | Steel for gear drive plate gear and method for producing the drive plate gear |
| JP2013036096A (en) * | 2011-08-09 | 2013-02-21 | Sanyo Special Steel Co Ltd | Steel for machine structure excellent in toughness |
| JP2019035126A (en) * | 2017-08-18 | 2019-03-07 | 大同特殊鋼株式会社 | Steel for machine structure use |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4193998B1 (en) | Machine structural steel excellent in machinability and manufacturing method thereof | |
| JP5777090B2 (en) | Steel for machine structural use with excellent surface fatigue strength | |
| JP4451808B2 (en) | Rolled steel bar for case hardening with excellent fatigue characteristics and grain coarsening resistance and its manufacturing method | |
| JPH0445574B2 (en) | ||
| JP3464356B2 (en) | Boron steel gear excellent in fatigue resistance and method of manufacturing the same | |
| JPH11350067A (en) | Free cutting hot working steel, coarse shape material, free cutting hot working product using them and production thereof | |
| JPH02115353A (en) | Metal band saw body material having high fatigue strength | |
| JPH0555585B2 (en) | ||
| EP1669468B1 (en) | Steel product for induction hardening, induction-hardened member using the same, and methods for producing them | |
| JP3932102B2 (en) | Case-hardened steel and carburized parts using the same | |
| JPH01129952A (en) | Steel for rotating parts having longer service life and exellent chip treatability | |
| JPH0266137A (en) | High-purity steel having superior machineability | |
| JP2615126B2 (en) | Gear steel | |
| WO2011155605A1 (en) | High-machinability high-strength steel and manufacturing method therefor | |
| JPH0734189A (en) | High strength bar steel excellent in machinability | |
| JP2576857B2 (en) | High strength non-tempered tough steel | |
| KR101984041B1 (en) | Case hardening steel | |
| JP2020169354A (en) | Steel for direct cutting | |
| JP2989766B2 (en) | Case hardened steel with excellent fatigue properties and machinability | |
| JP4906245B2 (en) | Machine structural steel with excellent machinability | |
| KR100380441B1 (en) | Alloy composition for transmission gear | |
| JP2003055743A (en) | Steel for cold die having excellent machinability | |
| JPH0576523B2 (en) | ||
| JP2004315840A (en) | Cold working tool steel superior in machinability, and manufacturing method therefor | |
| JPH07258793A (en) | Steel for carburized gear |