JPH06145889A - Free cutting steel - Google Patents
Free cutting steelInfo
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- JPH06145889A JPH06145889A JP4301096A JP30109692A JPH06145889A JP H06145889 A JPH06145889 A JP H06145889A JP 4301096 A JP4301096 A JP 4301096A JP 30109692 A JP30109692 A JP 30109692A JP H06145889 A JPH06145889 A JP H06145889A
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- cutting
- free
- cutting steel
- steel
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、工具寿命を延長させる
快削鋼、例えば機械構造物用鋼に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a free-cutting steel, such as a steel for machine structures, which prolongs tool life.
【０００２】[0002]
【従来の技術】従来より、硫黄快削鋼は、比較的広範な
切削加工様式において工具寿命を延長する効果を有する
ため広く使用されているが、疲労強度、横方向の靱性、
延性および塑性加工性が基本鋼に比べて劣るため適用範
囲や硫黄の添加量が限定される。2. Description of the Related Art Conventionally, sulfur free-cutting steel has been widely used because it has the effect of prolonging the tool life in a relatively wide range of cutting processing modes, but fatigue strength, lateral toughness,
Since the ductility and plastic workability are inferior to those of the basic steel, the applicable range and the amount of sulfur added are limited.
【０００３】鉛またはビスマス快削鋼は、機械的性質に
対する影響が比較的少ない快削鋼として比較的広い範囲
で使用されているが、浸炭焼き入れ材等の高強度鋼の疲
労強度や転動疲労強度を低下させるとともに横方向の靱
性、延性や熱間加工性が劣化する。また、近年の工具材
料の進歩による切削速度の高速化にともない、切削温度
の高い領域における鉛快削鋼の被削性が基本鋼に比べて
劣る場合が多くなっている。これは溶融鉛と超硬工具材
料の反応によるものであると考えられている。Lead or bismuth free-cutting steel is used in a relatively wide range as a free-cutting steel having a relatively small effect on mechanical properties, but fatigue strength and rolling of high strength steel such as carburized and hardened material. The fatigue strength is reduced and the transverse toughness, ductility and hot workability are deteriorated. Further, with the recent increase in cutting speed due to the progress of tool materials, the machinability of lead free-cutting steel in a region where the cutting temperature is high is often inferior to that of the basic steel. It is believed that this is due to the reaction between the molten lead and the cemented carbide tool material.
【０００４】Ｃａ快削鋼は、酸化物の形態（組成）を制
御することにより切削工具表面にベラーグと呼ばれる保
護層を形成して工具の拡散摩耗を抑制する快削鋼であ
る。この保護層の形成は工具表面近傍における温度と酸
化物の融点の影響を受ける。現在一般に製造されている
Ｃａ酸化物系快削鋼はＳｉ、Ａｌ、Ｃａの複合酸化物に
おいて最も低融点となるアノルサイトやゲーレナイトと
呼ばれる酸化物を生成させるものであり、超硬工具によ
る高速切削において工具寿命を延長する効果が認められ
ている。しかし、高速度工具鋼による穴あけや旋削、転
削等の低速切削において効果が小さいことから他の快削
成分（Ｐｂ、Ｓ）との複合快削鋼として製造される場合
が多い。この酸化物は機械的性質に及ぼす影響が小さい
が、酸化物の組成制御のためＡｌの含有量を極端に少な
くする必要がある。このため、浸炭焼入れや高周波焼入
れ等の高温の熱処理においてオーステナイト結晶粒の粗
大化を防止するＡｌＮが不足し、基本鋼に比べて疲労強
度が低下する場合がある。The Ca free-cutting steel is a free-cutting steel which controls the morphology (composition) of oxides to form a protective layer called a berag on the surface of the cutting tool to suppress the diffusion wear of the tool. The formation of this protective layer is affected by the temperature near the tool surface and the melting point of the oxide. Currently produced Ca oxide-based free-cutting steels are those that produce the oxides called anorthite and gerenite, which have the lowest melting points in the complex oxides of Si, Al, and Ca. The effect of extending the tool life is recognized. However, it is often produced as a composite free-cutting steel with other free-cutting components (Pb, S) because it has little effect in low-speed cutting such as drilling, turning, and rolling with high-speed tool steel. This oxide has little influence on the mechanical properties, but it is necessary to extremely reduce the Al content in order to control the composition of the oxide. Therefore, AlN that prevents coarsening of austenite crystal grains is insufficient in high-temperature heat treatment such as carburizing and induction hardening, and the fatigue strength may be lower than that of the basic steel.
【０００５】上記の快削成分を全て複合した３元快削鋼
は、あらゆる切削において工具寿命を延長する快削鋼と
して使用されているが、塑性加工性、疲労強度および靱
延性が基本鋼より劣るため適用範囲が限定されている。
従来の快削鋼の介在物としては、鉛快削鋼では低融点金
属（Ｐｂ、Ｂｉ）があり、硫黄快削鋼では硫化物（Ｍｎ
Ｓ）があり、Ｃａ快削鋼では低融点酸化物（ＳｉＯ2 −
ＣａＯ−Ａｌ2 Ｏ3 ）がある。The ternary free-cutting steel compounded with all of the above free-cutting components is used as a free-cutting steel for prolonging the tool life in any cutting, but its plastic workability, fatigue strength and toughness are superior to those of the basic steel. Its application range is limited because it is inferior.
As inclusions of conventional free-cutting steel, there are low melting point metals (Pb, Bi) in lead free-cutting steel, and sulfides (Mn in sulfur free-cutting steel).
S), and Ca free-cutting steel has a low melting point oxide (SiO 2 −
CaO-Al 2 O 3) is.
【０００６】[0006]
【発明が解決しようとする課題】従来の快削鋼の介在物
の被削性に対する影響を表１に示す。Table 1 shows the influence of conventional free-cutting steel inclusions on machinability.
【０００７】[0007]
【表１】 [Table 1]
【０００８】従来の快削鋼の介在物の強度、製造性に対
する影響を表２に示す。Table 2 shows the influence of inclusions of conventional free-cutting steel on the strength and manufacturability.
【０００９】[0009]
【表２】 [Table 2]
【００１０】さらに、従来の快削鋼の基本鋼に対する被
削性、強度、製造性の評価を表３に示す。Further, Table 3 shows the evaluation of machinability, strength, and manufacturability of the conventional free-cutting steel with respect to the basic steel.
【００１１】[0011]
【表３】 [Table 3]
【００１２】本発明は、前記の点に鑑みてなされたもの
で、広範な切削工具および切削条件において工具寿命を
延長し、疲労強度、靱延性、塑性加工性の良好な快削鋼
を提供することを目的とする。The present invention has been made in view of the above points, and provides a free-cutting steel which extends the tool life in a wide range of cutting tools and cutting conditions and has good fatigue strength, ductility and plastic workability. The purpose is to
【００１３】[0013]
【課題を解決するための手段】前記課題を解決するため
の本発明による快削鋼は、必須元素が Ｃ ：０．１０ 〜０．７５（重量％）、 Ｍｎ：０．１０ 〜２．５０（重量％）、 Ａｌ：０．００５〜０．０６０（重量％）、 Ｃａ：０．００２〜０．０１０（重量％）かつＣａ／Ａ
ｌ：０．１〜０．５、 Ｂ ：０．００３〜０．０１４（重量％）、 Ｎ ：０．００５〜０．０３０（重量％）かつＮ／
（１．３Ｂ＋０．２９Ｔｉ＋０．１５Ｚｒ＋０．１０Ｒ
ＥＭ）：０．７以上であって、 制限元素が Ｓｉ：０．３０（重量％）以下、 Ｏ ：０．００３（重量％）以下、 Ｓ ：０．０７（重量％）以下であって、 非金属介在物として六方晶窒化ほう素、ＣａＯ−Ａｌ2
Ｏ3 系酸化物およびＣａを１０％以上含有する硫化物を
含有することを特徴とする。In the free-cutting steel according to the present invention for solving the above problems, the essential elements are C: 0.10 to 0.75 (% by weight), Mn: 0.10 to 2.50. (Wt%), Al: 0.005-0.060 (wt%), Ca: 0.002-0.010 (wt%) and Ca / A
1: 0.1 to 0.5, B: 0.003 to 0.014 (% by weight), N: 0.005 to 0.030 (% by weight) and N /
(1.3B + 0.29Ti + 0.15Zr + 0.10R
EM): 0.7 or more, the limiting elements are Si: 0.30 (wt%) or less, O: 0.003 (wt%) or less, S: 0.07 (wt%) or less, Hexagonal boron nitride, CaO-Al 2 as non-metallic inclusions
It is characterized by containing an O 3 -based oxide and a sulfide containing 10% or more of Ca.
【００１４】本発明の快削鋼は、さらに上記の元素に加
え、１種または２種以上の選択元素が Ｃｒ：０．１ 〜２．０（重量％）、 Ｍｏ：０．０５ 〜１．０（重量％）、 Ｎｉ：０．１ 〜３．０（重量％）、 Ｖ ：０．０５ 〜０．５（重量％）、 Ｎｂ：０．００５〜０．１００（重量％）、 Ｔｅ：０．００２〜０．０８０（重量％） であることが望ましい。In the free-cutting steel of the present invention, in addition to the above elements, one or more selected elements are Cr: 0.1 to 2.0 (wt%), Mo: 0.05 to 1. 0 (wt%), Ni: 0.1 to 3.0 (wt%), V: 0.05 to 0.5 (wt%), Nb: 0.005 to 0.100 (wt%), Te: It is preferably 0.002 to 0.080 (% by weight).
【００１５】本発明による快削鋼の介在物は、六方晶窒
化ほう素（以下ＢＮという）およびＣａＯ−Ａｌ2 Ｏ3
系酸化物であり、この２種類の介在物が互いに補い合っ
て切削工具および切削条件に係わらず工具寿命を延長す
る。ＢＮ介在物の主な作用は切削工具表面の潤滑作用で
あり、ＣａＯ−Ａｌ2 Ｏ3 の主な作用は工具表面の保護
作用である。ＢＮ介在物は、高温でも潤滑性能が低下し
にくく、反応性が低いため低速から高速切削において有
効であるが、セラミックス工具における効果が小さいこ
とや、切削温度の高い超高速切削や高速重切削において
効果が小さい傾向がある。ＣａＯ−Ａｌ2 Ｏ3 系酸化物
は基本的に３ＣａＯ・Ａｌ2 Ｏ3 、１２ＣａＯ・７Ａｌ
2 Ｏ3 、ＣａＯ・Ａｌ2 Ｏ3 、ＣａＯ・２Ａｌ2 Ｏ3 、
ＣａＯ・６Ａｌ2 Ｏ3 またはこれに若干の酸化物形成元
素を含み、融点が１４００〜１７００℃となる酸化物で
あり、従来のＣａ快削鋼の介在物であるアノルサイトや
ゲーレナイトに比べてＳｉの含有量が低く、融点が高い
点で異なる。従って、切削温度の高い超高速切削や高速
重切削において特に有効であり、さらにアルミナを含有
する工具材種（特にアルミナコーティング超硬工具）に
有効である。The inclusions of the free-cutting steel according to the present invention are hexagonal boron nitride (hereinafter referred to as BN) and CaO-Al 2 O 3
It is a system oxide and these two kinds of inclusions complement each other to extend the tool life regardless of the cutting tool and cutting conditions. The main function of the BN inclusions is to lubricate the cutting tool surface, and the main function of CaO-Al 2 O 3 is to protect the tool surface. BN inclusions are effective in low-speed to high-speed cutting because their lubrication performance does not easily deteriorate even at high temperatures and their reactivity is low, but they are less effective in ceramic tools, and in ultra-high-speed cutting and high-speed heavy cutting with high cutting temperatures. The effect tends to be small. CaO-Al 2 O 3 based oxides are basically 3CaO · Al 2 O 3 and 12CaO · 7Al.
2 O 3 , CaO · Al 2 O 3 , CaO · 2Al 2 O 3 ,
CaO · 6Al 2 O 3 or an oxide containing a small amount of oxide forming elements and having a melting point of 1400 to 1700 ° C. They differ in that the content is low and the melting point is high. Therefore, it is particularly effective for ultra-high speed cutting and high-speed heavy cutting at high cutting temperature, and is also effective for tool material types containing alumina (especially alumina-coated cemented carbide tools).
【００１６】この２種類の介在物は微細であることと圧
延方向に展伸しにくいことより疲労強度、靱性、延性お
よび塑性加工性に影響を与えることなく被削性を向上す
る。また、本発明の快削鋼の酸化物制御には低酸素で、
大量のＣａの添加が必要であり、必然的に余剰のＣａが
硫化物を形成する。この硫化物はＣａＳまたは（Ｃａ．
Ｍｎ）Ｓであり、ＭｎＳに比べて熱間加工による展伸が
少ないため横方向の疲労強度、靱性、延性および塑性加
工性の劣化がＭｎＳに比べて小さい。また、アルミナを
含有する工具において、工具表面に保護層を形成して摩
耗を抑制する効果がある。また、従来のＣａ快削鋼では
介在物の形態制御のためＡｌの添加量を低く抑えるた
め、浸炭焼入れや高周波焼入れ等の高温の熱処理におい
て結晶粒が粗大化しやすいのに比べ、本発明の快削鋼で
は基本鋼と同等のＡｌ量の添加が可能であり、疲労強度
や靱性の低下がない。Since these two kinds of inclusions are fine and are difficult to spread in the rolling direction, they improve the machinability without affecting the fatigue strength, toughness, ductility and plastic workability. Moreover, low oxygen is used for controlling the oxides of the free-cutting steel of the present invention,
A large amount of Ca needs to be added, and excess Ca inevitably forms sulfides. This sulfide is CaS or (Ca.
Mn) S, which has less expansion due to hot working than MnS, and thus has less deterioration in fatigue strength, toughness, ductility, and plastic workability in the lateral direction than MnS. Further, in a tool containing alumina, there is an effect of forming a protective layer on the tool surface to suppress wear. In addition, in the conventional Ca free-cutting steel, the amount of Al added is kept low in order to control the morphology of inclusions, so the crystal grains tend to coarsen during high-temperature heat treatment such as carburizing and induction hardening. In cutting steel, it is possible to add the same amount of Al as in the basic steel, and there is no deterioration in fatigue strength or toughness.
【００１７】これにより従来の快削鋼より広範な切削工
具および切削条件において工具寿命延長効果を有し、あ
らゆる条件において基本鋼と同等またはそれ以上の疲労
強度、靱性、延性および塑性加工性が実現される。本発
明による快削鋼の介在物は六方晶窒化ほう素（ＢＮ）、
ＣａＯ−Ａｌ2 Ｏ 3 系酸化物および（Ｃａ、Ｍｎ）硫化
物であり、このために必要な添加元素はＢ、Ｎ、Ｃａ、
Ａｌである。ＢＮ介在物の生成には低酸素かつ高窒素で
あり、Ｔｉ、Ｚｒ、ＲＥＭ等のＢより窒化物形成能の高
い元素が少ないことが要求される。（特願昭６３−１５
４６０号参照）。また、ＣａＯ−Ａｌ2 Ｏ3 系酸化物お
よび（Ｃａ，Ｍｎ）Ｓを生成するためには多量のＣａの
添加が必要である。This allows a wider range of cutting work than conventional free-cutting steel.
It has the effect of extending the tool life under tools and cutting conditions.
Fatigue equivalent to or better than the basic steel under all conditions
Strength, toughness, ductility and plastic workability are achieved. Starting
The inclusions in free-cutting steel according to Ming are hexagonal boron nitride (BN),
CaO-Al2 O 3 -Based oxides and (Ca, Mn) sulfide
The additional elements necessary for this purpose are B, N, Ca,
It is Al. To produce BN inclusions, use low oxygen and high nitrogen.
Yes, it has a higher ability to form nitrides than B such as Ti, Zr, and REM.
It is required that there are few elements. (Japanese Patent Application Sho 63-15
460). In addition, CaO-Al2 O3 System oxide
And a large amount of Ca to produce (Ca, Mn) S
Needs to be added.
【００１８】本発明において必須元素はＣ、Ｍｎ、Ａ
ｌ、Ｃａ、Ｂ、Ｎであり、制限元素はＳｉ、Ｏ、Ｓであ
り、選択元素はＣｒ、Ｍｏ、Ｎｉ、Ｖ、Ｎｂ、Ｔｅであ
るが、これらの元素の限定理由を下記に示す。 (1) Ｃ ：０．１０ 〜０．７５（重量％） 下限を０．１０重量％としたのは強度確保のためであ
り、上限を０．７５重量％としたのは延性確保のためで
ある。In the present invention, the essential elements are C, Mn, A
1, Ca, B, and N, the limiting elements are Si, O, and S, and the selective elements are Cr, Mo, Ni, V, Nb, and Te. The reasons for limiting these elements are shown below. (1) C: 0.10 to 0.75 (wt%) The lower limit is 0.10 wt% to ensure strength, and the upper limit is 0.75 wt% to ensure ductility. is there.
【００１９】 (2) Ｍｎ：０．１０ 〜２．５０（重量％） 下限を０．１０重量％としたのは焼入れ性向上のためで
あり、上限を２．５０重量％としたのは被削性の確保の
ためである。 (3) Ａｌ：０．００５〜０．０６０（重量％） 下限を０．００５重量％としたのは酸化物制御、脱酸、
結晶粒度粗大化防止のためであり、上限を０．０６０重
量％としたのは酸化物制御のためである。(2) Mn: 0.10 to 2.50 (wt%) The lower limit of 0.10 wt% is for improving the hardenability, and the upper limit is 2.50 wt%. This is to ensure machinability. (3) Al: 0.005-0.060 (wt%) The lower limit of 0.005 wt% is oxide control, deoxidation,
This is for preventing the coarsening of the crystal grain size, and the upper limit of 0.060% by weight is for controlling the oxide.
【００２０】(4) Ｃａ：０．００２〜０．０１０（重量
％）、かつＣａ／Ａｌ：０．１〜０．５ 下限をＣａ：０．００２重量％、かつＣａ／Ａｌ：０．
１以上としたのは酸化物、硫化物形態制御のためであ
り、上限をＣａ：０．０１０重量％、かつＣａ／Ａｌ：
０．５以下としたのは酸化物形態制御のためである。(4) Ca: 0.002 to 0.010 (% by weight), and Ca / Al: 0.1 to 0.5 The lower limit is Ca: 0.002% by weight, and Ca / Al: 0.
1 or more is for controlling the form of oxides and sulfides, and the upper limit is Ca: 0.010% by weight and Ca / Al:
The reason why the ratio is 0.5 or less is for controlling the oxide morphology.
【００２１】 (5) Ｂ ：０．００３〜０．０１４（重量％） 下限を０．００３重量％としたのはＢＮ介在物のためで
あり、上限を０．０１４重量％としたのは熱間加工性の
ためである。 (6) Ｎ ：０．００５〜０．０３０（重量％）かつＮ／
（１．３Ｂ＋０．２９Ｔｉ＋０．１５Ｚｒ＋０．１０Ｒ
ＥＭ）：０．７以上 下限をＮ：０．００５重量％かつＮ／（１．３Ｂ＋０．
２９Ｔｉ＋０．１５Ｚｒ＋０．１０ＲＥＭ）：０．７重
量％としたのはＢＮ介在物、焼入れ性安定化のためであ
り、上限をＮ：０．０３０重量％としたのは延性のため
である。(5) B: 0.003 to 0.014 (% by weight) The lower limit is 0.003% by weight because of BN inclusions, and the upper limit is 0.014% by weight. This is because of the inter-workability. (6) N: 0.005-0.030 (wt%) and N /
(1.3B + 0.29Ti + 0.15Zr + 0.10R
EM): 0.7 or more The lower limit is N: 0.005% by weight and N / (1.3B + 0.
29Ti + 0.15Zr + 0.10REM): 0.7 wt% is for stabilizing BN inclusions and hardenability, and the upper limit is N: 0.030 wt% for ductility.
【００２２】(7) Ｓｉ：０．３０（重量％）以下 上限を０．０３０重量％としたのは酸化物形態制御のた
めである。 (8) Ｏ ：０．００３（重量％）以下 上限を０．００３重量％としたのは酸化物形態制御、疲
労強度のためである。 (9) Ｓ ：０．０７（重量％）以下 上限を０．０７重量％としたのは疲労強度、靱性のため
である。(7) Si: 0.30 (wt%) or less The upper limit of 0.030 wt% is for controlling the oxide morphology. (8) O: 0.003 (wt%) or less The upper limit is set to 0.003 wt% for the purpose of controlling oxide morphology and fatigue strength. (9) S: 0.07 (wt%) or less The upper limit is 0.07 wt% because of fatigue strength and toughness.
【００２３】 (10) Ｃｒ：０．１ 〜２．０（重量％） Ｍｏ：０．０５ 〜１．０（重量％） Ｎｉ：０．１ 〜３．０（重量％） 下限をＣｒ：０．１重量％、Ｍｏ：０．０５重量％、Ｎ
ｉ：０．１重量％としたのは焼入れ性、靱性確保のため
であり、上限をＣｒ：２．０重量％、Ｍｏ：１．０重量
％、Ｎｉ：３．０重量％としたのは被削性確保のためで
ある。(10) Cr: 0.1 to 2.0 (wt%) Mo: 0.05 to 1.0 (wt%) Ni: 0.1 to 3.0 (wt%) The lower limit is Cr: 0. 0.1% by weight, Mo: 0.05% by weight, N
i: 0.1% by weight is for ensuring hardenability and toughness, and the upper limits are Cr: 2.0% by weight, Mo: 1.0% by weight, and Ni: 3.0% by weight. This is to secure machinability.
【００２４】 (11) Ｖ ：０．０５ 〜０．５（重量％）、 Ｎｂ：０．００５〜０．１００（重量％）、 下限をＶ ：０．０５重量％、Ｎｂ：０．００５重量％
としたのは強度（フェライトの強化）確保のためであ
り、上限をＶ：０．５重量％、Ｎｂ：０．１００重量％
としたのは効果の飽和のためである。(11) V: 0.05 to 0.5 (wt%), Nb: 0.005 to 0.100 (wt%), the lower limit is V: 0.05 wt%, Nb: 0.005 wt %
The purpose is to secure the strength (strengthening of ferrite), and the upper limits are V: 0.5% by weight, Nb: 0.100% by weight.
The reason is that the effect is saturated.
【００２５】 (12) Ｔｅ：０．００２〜０．０８０（重量％） 下限を０．００２重量％としたのは硫化物の球状化入の
ためであり、上限を０．０８０重量％としたのは熱間加
工性のためである。本発明による快削鋼の介在物の被削
性に対する影響を表４に示す。(12) Te: 0.002 to 0.080 (% by weight) The lower limit is set to 0.002% by weight because of the spheroidization of sulfides, and the upper limit is set to 0.080% by weight. Is due to hot workability. Table 4 shows the influence of the inclusions of the free-cutting steel according to the present invention on the machinability.
【００２６】[0026]
【表４】 [Table 4]
【００２７】本発明による快削鋼の介在物の強度、製造
性に対する影響を表５に示す。Table 5 shows the influence of inclusions of free-cutting steel according to the present invention on the strength and manufacturability.
【００２８】[0028]
【表５】 [Table 5]
【００２９】さらに、本発明による快削鋼の基本鋼に対
する被削性、強度、製造性の評価を表６に示す。Table 6 shows the machinability, strength, and manufacturability of the free-cutting steel according to the present invention with respect to the basic steel.
【００３０】[0030]
【表６】 [Table 6]
【００３１】[0031]
【実施例】以下、本発明の実施例を説明する。まず供試
材の化学成分について述べる。炭素鋼（ＪＩＳ／Ｓ５５
Ｃ相当）系硫黄快削鋼、肌焼鋼（ＪＩＳ／ＳＣＭ４２０
相当）系高強度鋼、強靱鋼（Ｎｉ−Ｃｒ−Ｍｏ−Ｖ鋼）
を基本成分とする比較鋼およびそれぞれ基本成分を同じ
くする本発明による快削鋼（Ａ、Ｂ、Ｃ、Ｄ）を溶製し
た。さらに参考として従来の３元（Ｓ−Ｐｂ−Ｃａ）快
削鋼（Ｚ）を溶製した。EXAMPLES Examples of the present invention will be described below. First, the chemical composition of the test material will be described. Carbon steel (JIS / S55
C equivalent) type sulfur free-cutting steel, case hardening steel (JIS / SCM420
Equivalent) system high strength steel, tough steel (Ni-Cr-Mo-V steel)
Comparative steels having as a basic component and free-cutting steels (A, B, C, D) according to the present invention having the same basic components were melted. Further, as a reference, a conventional ternary (S-Pb-Ca) free-cutting steel (Z) was melted.
【００３２】Ａ、Ｂ、Ｃ、Ｄ、Ｚの成分組成を下記表７
に示す。The component compositions of A, B, C, D and Z are shown in Table 7 below.
Shown in.
【００３３】[0033]
【表７】 [Table 7]
【００３４】次に上記供試材の製造工程について述べ
る。７０ｔｏｎアーク炉溶解の後炉外精練し、インゴッ
ト鋳造を経て熱間圧延を行ってφ１００の丸棒を作成し
た。さらに被削性試験片、塑性加工性試験片用には熱処
理（焼きならし）をし、疲れ試験片、衝撃試験片用には
機械加工の後熱処理し、もう一度機械加工した。疲れ試
験片、衝撃試験片用の熱処理に際しては炭素鋼には高周
波焼入れ、肌焼鋼には浸炭焼入れ（９１０℃×５．５ｈ
ｒ．ＯＱ，１８０℃×１ｈｒ．ＡＣ）、強靱鋼には焼入
れ焼き戻し（８５０℃×０．５ｈｒ．ＯＱ，１５０℃×
１ｈｒ．ＡＣ）を行った。Next, the manufacturing process of the sample material will be described. After melting in a 70 ton arc furnace, refining outside the furnace, hot rolling was performed through ingot casting, and a φ100 round bar was prepared. Further, the machinability test piece and the plastic workability test piece were heat-treated (normalized), and the fatigue test piece and the impact test piece were heat-treated after machining and then machined again. In heat treatment for fatigue test pieces and impact test pieces, induction hardening is applied to carbon steel, and carburizing hardening is applied to case-hardened steel (910 ° C x 5.5h).
r. OQ, 180 ° C x 1 hr. AC), quenching and tempering for tough steel (850 ° C x 0.5 hr.OQ, 150 ° C x
1 hr. AC).
【００３５】こうして製作した試験片に対し、下記のよ
うな試験を行った。 (1) 切削試験 長手旋削加工、フライス加工、ドリル穴開けによる工具
寿命を評価した。その結果を表８に示す。The test pieces thus produced were subjected to the following tests. (1) Cutting test The tool life was evaluated by longitudinal turning, milling and drilling. The results are shown in Table 8.
【００３６】[0036]
【表８】 [Table 8]
【００３７】(2) 熱間加工性 φ１００ｍｍ圧延材の横方向切出し材のグリーブル（高
速熱間引張）試験における８００℃、１０００℃、１２
５０℃の絞り値を測定し比較鋼に対する比の平均を評価
した。 (3) 冷間加工性 静的圧縮試験における割れ発生限界圧縮率を評価した。(2) Hot workability 800 ° C., 1000 ° C., 12 in the greeble (high-speed hot tensile) test of the transversely cut material of φ100 mm rolled material
The aperture value at 50 ° C. was measured and the average ratio to comparative steel was evaluated. (3) Cold workability The crack initiation limit compression ratio in the static compression test was evaluated.
【００３８】(4) 疲労強度 φ１００ｍｍ圧延材から横方向に切出した平滑試験片の
小野式回転曲げ疲れ試験における１０7 疲れ強さを評価
した。 (5) 靱性 φ１００ｍｍ圧延材の横方向から切出したＲ１０ｍｍノ
ッチ試験片のシャルピー衝撃値を評価した。(4) Fatigue Strength A smooth test piece cut laterally from a φ100 mm rolled material was evaluated for 10 7 fatigue strength in the Ono-type rotary bending fatigue test. (5) Toughness The Charpy impact value of the R10 mm notch test piece cut out from the lateral direction of the φ100 mm rolled material was evaluated.
【００３９】以上の試験によって得られた本発明による
快削鋼の特性評価を下記表９に示す。The characteristic evaluation of the free-cutting steel according to the present invention obtained by the above test is shown in Table 9 below.
【００４０】[0040]
【表９】 [Table 9]
【００４１】[0041]
【発明の効果】以上説明したように、本発明の快削鋼に
よると、広い範囲の材質の切削工具および切削条件にお
いて工具寿命延長効果を有し、しかも基本鋼に対して製
造性や強度を全く劣化させないという効果がある。As described above, according to the free-cutting steel of the present invention, it has the effect of prolonging the tool life in a wide range of materials and cutting tools, and has the manufacturability and strength of the basic steel. It has the effect of not causing any deterioration.
Claims (2)
ｌ：０．１〜０．５、 Ｂ ：０．００３〜０．０１４（重量％）、 Ｎ ：０．００５〜０．０３０（重量％）かつＮ／
（１．３Ｂ＋０．２９Ｔｉ＋０．１５Ｚｒ＋０．１０Ｒ
ＥＭ）：０．７以上であって、 制限元素が Ｓｉ：０．３０（重量％）以下、 Ｏ ：０．００３（重量％）以下、 Ｓ ：０．０７（重量％）以下であって、 非金属介在物として六方晶窒化ほう素、ＣａＯ−Ａｌ2
Ｏ3 系酸化物およびＣａを１０％以上含有する硫化物を
含有することを特徴とする被削性および疲労強度に優れ
た快削鋼。1. An essential element is C: 0.10 to 0.75 (% by weight), Mn: 0.10 to 2.50 (% by weight), Al: 0.005 to 0.060 (% by weight), Ca: 0.002-0.010 (wt%) and Ca / A
1: 0.1 to 0.5, B: 0.003 to 0.014 (% by weight), N: 0.005 to 0.030 (% by weight) and N /
(1.3B + 0.29Ti + 0.15Zr + 0.10R
EM): 0.7 or more, the limiting elements are Si: 0.30 (wt%) or less, O: 0.003 (wt%) or less, S: 0.07 (wt%) or less, Hexagonal boron nitride, CaO-Al 2 as non-metallic inclusions
A free-cutting steel excellent in machinability and fatigue strength, characterized by containing an O 3 -based oxide and a sulfide containing 10% or more of Ca.
は２種以上の選択元素が Ｃｒ：０．１ 〜２．０（重量％）、 Ｍｏ：０．０５ 〜１．０（重量％）、 Ｎｉ：０．１ 〜３．０（重量％）、 Ｖ ：０．０５ 〜０．５（重量％）、 Ｎｂ：０．００５〜０．１００（重量％）、 Ｔｅ：０．００２〜０．０８０（重量％） であることを特徴とする被削性および疲労強度に優れた
快削鋼。2. In addition to the element according to claim 1, one or more selected elements are Cr: 0.1 to 2.0 (wt%), Mo: 0.05 to 1.0 (wt %), Ni: 0.1 to 3.0 (wt%), V: 0.05 to 0.5 (wt%), Nb: 0.005 to 0.100 (wt%), Te: 0.002 Free-cutting steel excellent in machinability and fatigue strength, characterized in that the free cutting steel is 0.080 (wt%).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4301096A JPH06145889A (en) | 1992-11-11 | 1992-11-11 | Free cutting steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4301096A JPH06145889A (en) | 1992-11-11 | 1992-11-11 | Free cutting steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06145889A true JPH06145889A (en) | 1994-05-27 |
Family
ID=17892808
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4301096A Pending JPH06145889A (en) | 1992-11-11 | 1992-11-11 | Free cutting steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06145889A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1518939A1 (en) * | 2002-07-03 | 2005-03-30 | Mitsubishi Steel Mfg. Co., Ltd. | Sulfur free cutting steel for machine structural use |
| EP2048257A1 (en) * | 2006-07-31 | 2009-04-15 | National Institute for Materials Science | Free-cutting stainless steel and process for producing the same |
| EP2733229A1 (en) * | 2011-07-15 | 2014-05-21 | Posco | Wire rod having superior hydrogen delayed fracture resistance, method for manufacturing same, high strength bolt using same and method for manufacturing bolt |
-
1992
- 1992-11-11 JP JP4301096A patent/JPH06145889A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1518939A1 (en) * | 2002-07-03 | 2005-03-30 | Mitsubishi Steel Mfg. Co., Ltd. | Sulfur free cutting steel for machine structural use |
| EP1518939A4 (en) * | 2002-07-03 | 2005-08-10 | Mitsubishi Steel Mfg | Sulfur free cutting steel for machine structural use |
| EP2048257A1 (en) * | 2006-07-31 | 2009-04-15 | National Institute for Materials Science | Free-cutting stainless steel and process for producing the same |
| EP2048257A4 (en) * | 2006-07-31 | 2012-11-28 | Nat Inst For Materials Science | Free-cutting stainless steel and process for producing the same |
| EP2733229A1 (en) * | 2011-07-15 | 2014-05-21 | Posco | Wire rod having superior hydrogen delayed fracture resistance, method for manufacturing same, high strength bolt using same and method for manufacturing bolt |
| EP2733229A4 (en) * | 2011-07-15 | 2015-04-08 | Posco | Wire rod having superior hydrogen delayed fracture resistance, method for manufacturing same, high strength bolt using same and method for manufacturing bolt |
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