JPH0288748A - Steel for machine structural use having excellent machinability - Google Patents
Steel for machine structural use having excellent machinabilityInfo
- Publication number
- JPH0288748A JPH0288748A JP24126588A JP24126588A JPH0288748A JP H0288748 A JPH0288748 A JP H0288748A JP 24126588 A JP24126588 A JP 24126588A JP 24126588 A JP24126588 A JP 24126588A JP H0288748 A JPH0288748 A JP H0288748A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- less
- machinability
- excellent machinability
- structural use
- 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 43
- 239000010959 steel Substances 0.000 title claims abstract description 43
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 20
- 229910052796 boron Inorganic materials 0.000 claims abstract description 12
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 11
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 10
- 239000012535 impurity Substances 0.000 claims abstract description 9
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 7
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 7
- 229910052802 copper Inorganic materials 0.000 claims abstract description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 6
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 6
- 229910052714 tellurium Inorganic materials 0.000 claims abstract description 6
- 229910052711 selenium Inorganic materials 0.000 claims abstract description 5
- 229910052791 calcium Inorganic materials 0.000 claims abstract description 4
- 229910052745 lead Inorganic materials 0.000 claims abstract description 4
- 229910052797 bismuth Inorganic materials 0.000 claims abstract description 3
- 229910000746 Structural steel Inorganic materials 0.000 claims description 9
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052793 cadmium Inorganic materials 0.000 claims 1
- 229910001563 bainite Inorganic materials 0.000 abstract description 10
- 229910052719 titanium Inorganic materials 0.000 abstract description 7
- 229910001567 cementite Inorganic materials 0.000 abstract description 4
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 abstract description 4
- 238000001556 precipitation Methods 0.000 abstract description 3
- 238000007670 refining Methods 0.000 abstract description 3
- 229910052759 nickel Inorganic materials 0.000 abstract description 2
- 229910052717 sulfur Inorganic materials 0.000 abstract description 2
- 238000003754 machining Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 238000005520 cutting process Methods 0.000 description 7
- 229920006395 saturated elastomer Polymers 0.000 description 7
- 229910000734 martensite Inorganic materials 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000005728 strengthening Methods 0.000 description 1
- 238000005496 tempering Methods 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、調質することなく引張り強度が７０ｋｇ ｆ
／−以上を有する被削性の優れた機械構造用鋼に関す
るものである。[Detailed description of the invention] [Industrial application field] The present invention has a tensile strength of 70 kg f without refining.
The present invention relates to a mechanical structural steel having excellent machinability of /- or more.
［従来技術］
機械部品の製造における最終的な工程として切削作業は
不可欠である。しかし、切削工程における省コスト、省
力化、生産性の向上から、より高速で切削できる材料が
望まれている。従来、引張り強度が７０ｋｇｆ／−を超
えるような機械部品には、０．３〜０．６％Ｃを含む機
械構造用鋼に焼入れ、焼きもどしの熱処理を施したもの
が用いられている。このような材料の切削においては、
鋼中に析出したセメンタイトが工具の摩耗を促進するた
め、切削速度の高速化の妨げとなっている。[Prior Art] Cutting work is essential as the final process in manufacturing mechanical parts. However, in order to save costs, save labor, and improve productivity in the cutting process, materials that can be cut at higher speeds are desired. Conventionally, mechanical structural steel containing 0.3 to 0.6% C has been heat-treated by quenching and tempering for mechanical parts having a tensile strength exceeding 70 kgf/-. When cutting such materials,
Cementite precipitated in steel accelerates tool wear and is an impediment to increasing cutting speeds.
従って、このような組織を何らかの方法で改善すること
が望ましい。「鉄と鋼 ６８ （１９８２）Ａ８１」で
は、フェライト中にマルテンサイトが分布する組織が提
案され、切りくず処理性が主に改善されている。しかし
、この方法ではマルテンサイト量の制御が熱処理で行わ
れており、しがもその温度管理、保持時間管理が面倒で
ある。Therefore, it is desirable to improve such organization in some way. "Tetsu to Hagane 68 (1982) A81" proposes a structure in which martensite is distributed in ferrite, and chip control is mainly improved. However, in this method, the amount of martensite is controlled by heat treatment, and temperature management and holding time management are troublesome.
また、熱処理を必要としないものとして、Ｃ量が０．０
２〜０．０５％の低Ｃベイナイト組織を有した鋼が特開
昭６３−１１１１６０号公報に開示されている。従来の
焼入れ、焼きもどし鋼に比べて良好な被削性を持ってい
るものの、被削性に対する要求は際限無く、さらに被削
性の優れた鋼が求められている。In addition, as one that does not require heat treatment, the amount of C is 0.0
A steel having a low C bainite structure of 2 to 0.05% is disclosed in JP-A-63-111160. Although it has better machinability than conventional hardened and tempered steel, there is no limit to the demands on machinability, and steel with even better machinability is being sought.
［発明が解決しようとする課題］
本発明は、以上のような従来の問題を解決するために、
考え出された機械構造用鋼で、熱間圧延あるいは熱間鍛
造のまま、または場合によっては焼きならしのままで調
質することなく、セメンタイトの析出を抑えた高速切削
における被削性の優れな低炭素ベイナイト主体の組織を
有する鋼を提供することを目的とする。[Problems to be solved by the invention] In order to solve the conventional problems as described above, the present invention solves the following problems:
This is a newly developed mechanical structural steel that has excellent machinability in high-speed cutting with suppressed cementite precipitation without the need for heat-refining in hot-rolled or hot-forged, or in some cases, normalized condition. The purpose of the present invention is to provide a steel having a low carbon bainite-based structure.
［課題を解決するための手段］
前記目的を達成するために、本発明は以下に述べる成分
組成の機械構造用鋼とする。[Means for Solving the Problems] In order to achieve the above object, the present invention provides a mechanical structural steel having the following composition.
（１） 重量％で、
Ｃ：０．０２％未満、 Ｓｉ：０．１〜１．０％
、Ｍ ｎ ： １．０〜３．５％、 Ｃｒ＋Ｍｎ ：
２．０〜５．５％、Ｔ ｉ ： ０．００５〜０．０３
％、 Ｂ ： ０．０００３〜０．００３％、Ａｌ：
０．０１〜０．０５％、 Ｎ ： ０．００６％以
下を含み、残部はＦｅ及び不可避不純物からなる被削性
の優れた機械構造用鋼。(1) In weight%, C: less than 0.02%, Si: 0.1 to 1.0%
, Mn: 1.0-3.5%, Cr+Mn:
2.0-5.5%, Ti: 0.005-0.03
%, B: 0.0003-0.003%, Al:
0.01 to 0.05%, N: 0.006% or less, and the remainder is Fe and unavoidable impurities. A mechanical structural steel with excellent machinability.
（２） 重量％で、
Ｃ：０．０２％未満、 Ｓｉ：０．１〜１．０％、
Ｍ ｎ ： １．０〜３．５％、 Ｃｒ ＋Ｍ ｎ
： ２．０〜５．５％、Ｔ ｉ ： ０．００５〜０，
０３％、 Ｂ ： ０．０００３〜０．００３％、Ａ
ｌ：０．０１〜０．０５％、 Ｎ ： ０．００６
％以下を含み、更に、
Ｎｉ：１．０％以下、 Ｃｕ：１．０％以下、Ｍｏ
：０．５％以下、 Ｎｂ：０．０５％以下、Ｖ
：０．１％以下、
のうちの１種もしくは２種以上を含み、残部はＦｅ及び
不可避不純物からなる被削性の優れた機械構造用鋼。(2) In weight%, C: less than 0.02%, Si: 0.1 to 1.0%,
Mn: 1.0-3.5%, Cr+Mn
: 2.0-5.5%, Ti: 0.005-0,
03%, B: 0.0003-0.003%, A
l: 0.01-0.05%, N: 0.006
% or less, further including Ni: 1.0% or less, Cu: 1.0% or less, Mo
: 0.5% or less, Nb: 0.05% or less, V
: 0.1% or less, containing one or more of the following, with the remainder being Fe and unavoidable impurities. Steel for machine structures with excellent machinability.
（３） 重量％で、
Ｃ：０．０２％未満、 Ｓｉ：０．１〜１．０％、
Ｍ ｎ ： １．０〜３．５％、 Ｃｒ ＋Ｍ ｎ
： ２．０〜５．５％、Ｔ ｉ ： ０．００５〜０．
０３％、 Ｂ ： ０．０００３〜０．００３％、Ａ
ｌ：０．０１〜０．０５％、 Ｎ ： ０．００６
％以下＝６−
を含み、更に、
Ｓ ： ０．０１〜０．１５％、 Ｔ ｅ ： Ｏ
，Ｏ１〜０．１５％、Ｓ ｅ ： ０．０１〜０．１５
％、 Ｐ ｂ ： ０．０４〜０．３５％、Ｂ ｉ
： ０．０４〜０．３５％、 Ｃａ ： ０．０００
５〜０．０１％、のうちの１種もしくは２種以上を含み
、残部はＦｅ及び不可避不純物からなる被削性の優れた
機械構造用鋼。(3) In weight%, C: less than 0.02%, Si: 0.1 to 1.0%,
Mn: 1.0-3.5%, Cr+Mn
: 2.0-5.5%, Ti: 0.005-0.
03%, B: 0.0003-0.003%, A
l: 0.01-0.05%, N: 0.006
% or less = 6-, furthermore, S: 0.01-0.15%, Te: O
, O1-0.15%, S e : 0.01-0.15
%, Pb: 0.04-0.35%, B i
: 0.04-0.35%, Ca: 0.000
5 to 0.01% of one or more of the following, with the remainder being Fe and unavoidable impurities. Steel for machine structures with excellent machinability.
（４） 重量％で、
Ｃ：０．０２％未満、 Ｓｉ：０．１〜１．０％、
Ｍ ｎ ： １．０〜３．５％、 Ｃｒ ＋ Ｍ ｎ
： ２．０〜５．５％、Ｔ ｉ ： ０．００５〜０
．０３％、 Ｂ ： ０．０００３〜０．００３％、
Ａｌ：０．０１〜０．０５％、 Ｎ ： ０．００
６％以下を含み、更に、
Ｎｉ：１．０％以下、 Ｃｕ：１．０％以下、Ｍｏ
：０．５％以下、 Ｎｂ：０．０５％以下、Ｖ
：０．１％以下、
のうちの１種もしくは２種以上を含み、更に、Ｓ ：
０．０１〜０．１５％、 Ｔ ｅ ： ０．０１〜
０．１５％、Ｓ ｅ ： ０．０１〜０．１５％、
Ｐ ｂ ： ０．０４〜０．３５％、Ｂ ｉ ： ０．
０４〜０．３５％、 Ｃａ ： ０．０００５〜０．
０１％、のうちの１種もしくは２種以上を含み、残部は
Ｆｅ及び不可避不純物からなる被削性の優れた機械構造
用鋼。(4) In weight%, C: less than 0.02%, Si: 0.1 to 1.0%,
Mn: 1.0-3.5%, Cr+Mn
: 2.0-5.5%, Ti: 0.005-0
．． 03%, B: 0.0003-0.003%,
Al: 0.01-0.05%, N: 0.00
Contains 6% or less, and further includes Ni: 1.0% or less, Cu: 1.0% or less, Mo
: 0.5% or less, Nb: 0.05% or less, V
: 0.1% or less, contains one or more of the following, furthermore, S:
0.01~0.15%, Te: 0.01~
0.15%, Se: 0.01-0.15%,
Pb: 0.04-0.35%, Bi: 0.
04-0.35%, Ca: 0.0005-0.
01%, with the remainder consisting of Fe and unavoidable impurities, and has excellent machinability.
［作用］
この発明に係る機械構造用鋼の化学成分の限定理由につ
いて述べる。[Function] The reason for limiting the chemical composition of the mechanical structural steel according to the present invention will be described.
Ｓｉ： 脱酸に必要な元素であり、同時に強化元素でも
ある。０．１％未満では、十分な脱酸効果が得られない
ので、０．１％以上とした。また１、０％を超えて添加
しても添加効果が飽和するので１．０％を上限とした。Si: An element necessary for deoxidation and a strengthening element at the same time. If it is less than 0.1%, a sufficient deoxidizing effect cannot be obtained, so it is made to be 0.1% or more. Furthermore, even if it is added in an amount exceeding 1.0%, the effect of addition is saturated, so 1.0% is set as the upper limit.
Ｍｎ： Ｃ，Ｃｒと同様、強度・靭性に大きな影響を
与える元素である。１．００％未満では十分な強度・靭
性が得られないため、１．００％以上とした。３．５０
％を越すと靭性を損なう場合があるので、３．５０％以
下とした。Mn: Similar to C and Cr, Mn is an element that greatly affects strength and toughness. If it is less than 1.00%, sufficient strength and toughness cannot be obtained, so it is set to 1.00% or more. 3.50
If it exceeds 3.5%, the toughness may be impaired, so it was set to 3.50% or less.
Ｃｒ： Ｍｎ、Ｃと同様に強度・靭性を確保するため
に重要な元素である。Ｃｒ＋Ｍｎ量で２．００％未満で
あると強度が不足するため、２．００％以上とした。ま
た、５．５０％を超えて添加しても添加効果が飽和する
ので５．５０％以下とした。Cr: Like Mn and C, this is an important element for ensuring strength and toughness. If the Cr+Mn content is less than 2.00%, the strength will be insufficient, so it is set to 2.00% or more. Moreover, even if it is added in excess of 5.50%, the effect of addition is saturated, so it is set at 5.50% or less.
Ｔｉ： 鋼中のＮを固定し、Ｂの持つ焼入れ性向上効果
を確保するために添加する。０．００５％未満では、Ｎ
を固定する効果が十分でないなめ、０．００５％以上と
した。また、０．０３０％を超えて添加しても効果が飽
和すること、および過剰のＴｉＮの生成により被削性、
疲労特性、靭性を損なうことがあるため、０．０３０％
以下とした。Ti: Added to fix N in steel and ensure the hardenability improvement effect of B. At less than 0.005%, N
If the effect of fixing is not sufficient, it was set to 0.005% or more. In addition, even if it is added in excess of 0.030%, the effect will be saturated, and the machinability will deteriorate due to the generation of excessive TiN.
0.030% as it may impair fatigue properties and toughness.
The following was made.
Ｂ ： 焼入れ性を向上させるために添加する。０．０
００３％未満ではこの効果が少ないなめに、これを０．
０００３％以上とした。また、０．００３０％を超えて
添加しても効果が飽和するため、０．００３０％以下と
した。B: Added to improve hardenability. 0.0
If it is less than 0.003%, this effect is small, so it is set to 0.003%.
0003% or more. Moreover, since the effect is saturated even if added in excess of 0.0030%, the content was set at 0.0030% or less.
Ａｌ二 強力な脱酸効果を持つため添加する。Al2 Added because it has a strong deoxidizing effect.
０．０１％未満ではこの効果が認められなくなるので、
０．０１％以上とした。０．０５％を越して添加しても
、効果が飽和するので０．０５％５％
以上した。If it is less than 0.01%, this effect will not be observed, so
The content was set to 0.01% or more. Even if it is added in excess of 0.05%, the effect will be saturated, so the amount was set at 0.05% or more.
”Ｎ： ０．００６０％を越すとＮを固定させるため
に必要なＴｉの量が多くなり、大量のＴｉＮの存在によ
り被削性、疲労特性、靭性が低下することがあるため、
０．００６０％以下とした。``N: If it exceeds 0.0060%, the amount of Ti required to fix N increases, and the presence of a large amount of TiN may deteriorate machinability, fatigue properties, and toughness.
It was set to 0.0060% or less.
Ｃ： 本発明鋼の組織を被削性に優れたベイナイト組織
にするための基本的添加元素である。第１図は、被削性
に及ぼす炭素量の影響について示した図である。これは
重量％で、Ｓｉ：０．１０〜１．００％、Ｍｎ ＋ ０
．６０〜３．５０％、Ｃｒ＋Ｍｎ ： ２．５０−５．
５０％、Ｔｉ ：０．００１〜０．０３０％、Ｂ：０．
００１〜０．０３０％、Ａｔ ：０．０１〜０．０５％
、Ｎ：０．００６０％以下を含む基本成分系にＣを０．
００５％から０．１５％まで調整した鋼を供試材として
用いて、ＡＣ３変態点以上に加熱後、熱間圧延し放冷し
て試験片を採取し、そして被削性を調査した結果である
。全てベイナイト組織の試料で、同一引張り強度（７５
±１ ｋｇ ｆ ／ ｔｍ＆ ）に調整して行った。炭
素レベルを０．０２％未満とすることによリ、優れた被
削性を得られることが分かる。従って、本発明では炭素
量を０．０２％未満とした。C: A basic additive element for forming the structure of the steel of the present invention into a bainite structure with excellent machinability. FIG. 1 is a diagram showing the influence of carbon content on machinability. This is weight%, Si: 0.10-1.00%, Mn + 0
．． 60-3.50%, Cr+Mn: 2.50-5.
50%, Ti: 0.001-0.030%, B: 0.
001-0.030%, At: 0.01-0.05%
, N: 0.0060% or less of C in the basic component system containing 0.0060% or less.
Using steel adjusted from 0.005% to 0.15% as a test material, it was heated to above the AC3 transformation point, then hot rolled and allowed to cool to take a test piece, and the machinability was investigated. be. All samples had a bainite structure and had the same tensile strength (75
It was adjusted to ±1 kg f/tm & ). It can be seen that excellent machinability can be obtained by keeping the carbon level below 0.02%. Therefore, in the present invention, the carbon content is set to less than 0.02%.
なお、図中の被削性指数は、焼入れ焼きもどし材（炭素
量０１４５％、引張り強度７５ｋｇｆ／ｍｎＴである第
１表の第２２鋼）を基準としたとき、同一時間の工具寿
命が得られる切削速度の比で示している。In addition, the machinability index in the figure is based on the quenched and tempered material (No. 22 steel in Table 1, which has a carbon content of 0145% and a tensile strength of 75 kgf/mnT), and the tool life for the same amount of time is obtained. It is shown as a ratio of cutting speed.
Ｎｉ、Ｃｕ、Ｍｏ、Ｎｂ、Ｖ ： 強化元素であり
、必要に応じて一種または二種以上を添加してもよいが
、添加の効果が飽和するので、Ｎｉは１％以下、Ｃｕは
１％以下、Ｍｏは０．５％以下とするのが好ましい。Ｎ
ｂ、Ｖについては、靭性を確保する点からそれぞれ０．
０５％以下、０．１０％以下とするのが好ましい。Ni, Cu, Mo, Nb, V: These are reinforcing elements, and one or more of them may be added as needed, but the effect of addition will be saturated, so Ni should be 1% or less and Cu should be 1% or less. Hereinafter, it is preferable that Mo be 0.5% or less. N
b and V are each set to 0.0 from the viewpoint of ensuring toughness.
It is preferably 0.05% or less and 0.10% or less.
ｓ、ｐｂ ： 中・低速での被削性も対象になる場
合には、有効な被削性を保証するために、少なくとも一
種を添加するのが好ましい。Ｓは０．０１〜０．１５％
とするのが望ましい。s, pb: When machinability at medium and low speeds is also a target, it is preferable to add at least one of them to ensure effective machinability. S is 0.01-0.15%
It is desirable to do so.
０．０１％未満では効果が少なく、０．１５％を越える
と靭性を低下させる。ｐｂは０．０４〜０．３５％とす
るのが望ましい。０．０４％未満では効果が少なく、０
．３５％を超えると添加効果が飽和する。また、Ｓにつ
いてはその一部または総てをＴｅ、Ｓｅの一種または二
種と置き換えてもよく、ｐｂについてはその一部または
総てをＢｉと置き換えてもよい。If it is less than 0.01%, the effect will be small, and if it exceeds 0.15%, the toughness will be reduced. It is desirable that pb be 0.04 to 0.35%. Less than 0.04% has little effect;
．． If it exceeds 35%, the effect of addition is saturated. Furthermore, part or all of S may be replaced with one or both of Te and Se, and part or all of pb may be replaced with Bi.
Ｃａ： 高速における被削性をさらに向上させる元素で
あり、その有効性から０．０００５〜０．０１％とする
のが好ましい。Ca: An element that further improves machinability at high speeds, and from its effectiveness it is preferably set at 0.0005 to 0.01%.
０ ： 本発明の必要要件ではないが、ｏ、ｏｏｉｏ％
以下にすることにより更に被削性及び疲労特性を向上す
ることができる元素である。0: Although not a necessary requirement of the present invention, o, ooio%
It is an element that can further improve machinability and fatigue characteristics by using the following.
本発明鋼は熱間圧延もしくは熱間鍛造のまま、または場
合によっては焼きならしのままでもベイナイト組織を主
体とする微視的組織を有する被削性の優れた機械構造用
鋼が得られる。すなわち、低炭素ベイナイト組織として
、被削性に有害なセメンタイトの析出を抑えることによ
り、被削性を向上させることができる。なお、本発明鋼
の組織はベイナイトを主体とするが、フェライト、マル
テンサイトまたは残留オーステナイトの一種または二種
以上との混合組織でもよい。The steel of the present invention can be used as it is hot rolled or hot forged, or in some cases as normalized as it is, to obtain a mechanical structural steel having a microstructure mainly composed of bainite structure and having excellent machinability. That is, as a low carbon bainite structure, machinability can be improved by suppressing the precipitation of cementite that is harmful to machinability. The structure of the steel of the present invention is mainly composed of bainite, but may be a mixed structure with one or more of ferrite, martensite, or retained austenite.
［発明の実施例］
（実施例）
実施例で本発明の効果を具体的に述べる。第１表に示す
化学成分からなる鋼、すなわち鋼Ｎａ １〜Ｎａ ２０
は本発明鋼、鋼Ｎｏ、２１〜Ｎ０．２８は比較鋼である
。[Examples of the Invention] (Examples) The effects of the present invention will be specifically described in Examples. Steel consisting of chemical components shown in Table 1, i.e. steel Na 1 to Na 20
is the invention steel, steel No. 21 to No. 0.28 are comparative steels.
鋼Ｎｏ、 １〜Ｎｏ、 ５ 、Ｎｏ、 ７〜Ｎ［Ｌ ２
０ 、及び鋼ＮＩＬ２５〜Ｎ［Ｌ２８は、鋼片をＡＣ３
変態点以上に加熱し、３０ｍｍ’φの丸鋼に圧延しその
まま放冷したものである。Steel No, 1~No, 5, No, 7~N [L 2
0, and steel NIL25~N [L28 is the steel billet AC3
It was heated above the transformation point, rolled into a round steel of 30 mm'φ, and left to cool.
また、鋼ＮＬ６は３０ｍｍφに圧延後、９５０℃、６０
分で焼きならしたものである。鋼Ｎａ １〜Ｎ［Ｌ２０
、及び鋼Ｎ［Ｌ２５〜Ｎ［Ｌ２８は、いずれもベイナイ
ト組織である。鋼ＮＱ、２１〜Ｎ［１，２３は、３０ｍ
ｍφの丸鋼を８５０℃で焼入れし６５０℃で焼きもどし
したもので、焼きもどしマルテンサイト組織である。鋼
Ｎ０．２４は３０ｍｍφの丸鋼を８５０℃で加熱後７０
０℃で保持し焼入れし、３００℃で焼きもどししたもの
でマルテンサイトがフェライト中に分布する組織である
。In addition, after rolling steel NL6 to 30 mmφ, it was heated at 950°C and 60°C.
It is roasted for a few minutes. Steel Na 1~N[L20
, and Steel N[L25 to N[L28] all have a bainite structure. Steel NQ, 21~N [1, 23 is 30m
mφ round steel is hardened at 850°C and tempered at 650°C, and has a tempered martensitic structure. Steel N0.24 is a 30mmφ round steel heated to 850℃ and then heated to 70℃.
It is held and quenched at 0°C and tempered at 300°C, and has a structure in which martensite is distributed in ferrite.
上述の方法で処理した３０ｍｍφの丸鋼の供試体を超硬
工具を用いて旋削したときの被削性指数と被剛材の強度
を第１表に示す。被削性指数とは、同一時間の工具寿命
で得られる切削速度を比較鋼Ｎ［Ｌ ２２を基準とした
ときの比で示したものである。Table 1 shows the machinability index and the strength of the rigid material when a 30 mmφ round steel specimen treated in the above method was turned using a carbide tool. The machinability index is expressed as a ratio of the cutting speed obtained with the same tool life over the comparative steel N[L 22.
本発明鋼は同一引張り強度レベルにおいて、比較鋼Ｎａ
２１．２２．２３．２４．２７および２８に比べて、優
れた被削性を有していることが分かる。また、比較鋼Ｎ
ａ２５および２６については被削性は、良好であるもの
の、強度は不十分となっている。０を０．００１０％以
下とした鋼Ｎα２０は、同一引張り強度レベルの鋼Ｎ［
Ｌ ３と比べ、被削性に優れている。また、鋼Ｎ［Ｌｌ
は同一引張り強度レベルの特開昭６３−１１１１６０号
公報に記載された鋼Ｎ［Ｌ２８に比べて被削性に優れて
いる。At the same tensile strength level, the steel of the present invention has a Na
It can be seen that it has excellent machinability compared to No. 21, 22, 23, 24, 27 and 28. Also, comparative steel N
Although the machinability of a25 and a26 is good, the strength is insufficient. Steel Nα20 in which 0 is 0.0010% or less is steel N[
Excellent machinability compared to L3. Also, steel N [Ll
is superior in machinability to steel N [L28 described in JP-A-63-111160, which has the same tensile strength level.
［発明の効果］
以上のとおり、本発明によれば、低炭素ベイナイト組織
を主体とする被削性の良好な機械構造用鋼が得られる効
果がある。[Effects of the Invention] As described above, according to the present invention, there is an effect that a steel for mechanical structures having good machinability mainly having a low carbon bainite structure can be obtained.
第１図は、Ｃを０．００５％から０．１５％までに調整
した鋼のＣ含有量と被削性指数の関係を示す図である。FIG. 1 is a diagram showing the relationship between C content and machinability index of steels with C adjusted from 0.005% to 0.15%.
Claims (4)
１．０〜３．５％、Ｃｒ＋Ｍｎ：２．０〜５．５％、Ｔ
ｉ：０．００５〜０．０３％、Ｂ：０．０００３〜０．
００３％、Ａｌ：０．０１〜０．０５％、Ｎ：０．００
６％以下を含み、残部はＦｅ及び不可避不純物からなる
被削性の優れた機械構造用鋼。(1) In weight%, C: less than 0.02%, Si: 0.1-1.0%, Mn:
1.0-3.5%, Cr+Mn: 2.0-5.5%, T
i: 0.005-0.03%, B: 0.0003-0.
003%, Al: 0.01-0.05%, N: 0.00
A mechanical structural steel with excellent machinability, containing 6% or less, with the remainder consisting of Fe and unavoidable impurities.
１．０〜３．５％、Ｃｒ＋Ｍｎ：２．０〜５．５％、Ｔ
ｉ：０．００５〜０．０３％、Ｂ：０．０００３〜０．
００３％、Ａｌ：０．０１〜０．０５％、Ｎ：０．００
６％以下を含み、更に、 Ｎｉ：１．０％以下、Ｃｕ：１．０％以下、Ｍｏ：０．
５％以下、Ｎｂ：０．０５％以下、Ｖ：０．１％以下、 のうちの１種もしくは２種以上を含み、残部はＦｅ及び
不可避不純物からなる被削性の優れた機械構造用鋼。(2) In weight%, C: less than 0.02%, Si: 0.1-1.0%, Mn:
1.0-3.5%, Cr+Mn: 2.0-5.5%, T
i: 0.005-0.03%, B: 0.0003-0.
003%, Al: 0.01-0.05%, N: 0.00
6% or less, and further contains Ni: 1.0% or less, Cu: 1.0% or less, Mo: 0.
5% or less, Nb: 0.05% or less, V: 0.1% or less, and the remainder is Fe and unavoidable impurities. Steel for mechanical structures with excellent machinability. .
１．０〜３．５％、Ｃｒ＋Ｍｎ：２．０〜５．５％、Ｔ
ｉ：０．００５〜０．０３％、Ｂ：０．０００３〜０．
００３％、Ａｌ：０．０１〜０．０５％、Ｎ：０．００
６％以下を含み、更に、 Ｓ：０．０１〜０．１５％、Ｔｅ：０．０１〜０．１５
％、Ｓｅ：０．０１〜０．１５％、Ｐｂ：０．０４〜０
．３５％、Ｂｉ：０．０４〜０．３５％、Ｃｄ：０．０
００５〜０．０１％、のうちの１種もしくは２種以上を
含み、残部はＦｅ及び不可避不純物からなる被削性の優
れた機械構造用鋼。(3) In weight%, C: less than 0.02%, Si: 0.1-1.0%, Mn:
1.0-3.5%, Cr+Mn: 2.0-5.5%, T
i: 0.005-0.03%, B: 0.0003-0.
003%, Al: 0.01-0.05%, N: 0.00
Contains 6% or less, and further includes: S: 0.01 to 0.15%, Te: 0.01 to 0.15
%, Se: 0.01-0.15%, Pb: 0.04-0
．． 35%, Bi: 0.04-0.35%, Cd: 0.0
0.005 to 0.01%, with the remainder being Fe and unavoidable impurities.
１．０〜３．５％、Ｃｒ＋Ｍｎ：２．０〜５．５％、Ｔ
ｉ：０．００５〜０．０３％、Ｂ：０．０００３〜０．
００３％、Ａｌ：０．０１〜０．０５％、Ｎ：０．００
６％以下を含み、更に、 Ｎｉ：１．０％以下、Ｃｕ：１．０％以下、Ｍｏ：０．
５％以下、Ｎｂ：０．０５％以下、Ｖ：０．１％以下、 のうちの１種もしくは２種以上を含み、更に、Ｓ：０．
０１〜０．１５％、Ｔｅ：０．０１〜０．１５％、Ｓｅ
：０．０１〜０．１５％、Ｐｂ：０．０４〜０．３５％
、Ｂｉ：０．０４〜０．３５％、Ｃａ：０．０００５〜
０．０１％、のうちの１種もしくは２種以上を含み、残
部はＦｅ及び不可避不純物からなる被削性の優れた機械
構造用鋼。(4) In weight%, C: less than 0.02%, Si: 0.1-1.0%, Mn:
1.0-3.5%, Cr+Mn: 2.0-5.5%, T
i: 0.005-0.03%, B: 0.0003-0.
003%, Al: 0.01-0.05%, N: 0.00
6% or less, and further contains Ni: 1.0% or less, Cu: 1.0% or less, Mo: 0.
5% or less, Nb: 0.05% or less, V: 0.1% or less, and further contains one or more of the following: S: 0.
01-0.15%, Te: 0.01-0.15%, Se
:0.01~0.15%, Pb:0.04~0.35%
, Bi: 0.04~0.35%, Ca: 0.0005~
A mechanical structural steel with excellent machinability, containing one or more of the following: 0.01%, with the remainder consisting of Fe and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24126588A JPH0288748A (en) | 1988-09-27 | 1988-09-27 | Steel for machine structural use having excellent machinability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24126588A JPH0288748A (en) | 1988-09-27 | 1988-09-27 | Steel for machine structural use having excellent machinability |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0288748A true JPH0288748A (en) | 1990-03-28 |
Family
ID=17071682
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24126588A Pending JPH0288748A (en) | 1988-09-27 | 1988-09-27 | Steel for machine structural use having excellent machinability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0288748A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5532723A (en) * | 1991-09-30 | 1996-07-02 | Rohm Co., Ltd. | Drive IC for a printing head |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61238941A (en) * | 1985-04-15 | 1986-10-24 | Kobe Steel Ltd | Untempered steel for hot forging |
| JPS63111160A (en) * | 1986-10-30 | 1988-05-16 | Nkk Corp | High toughness non-heattreated steel for hot forging |
| JPS63166949A (en) * | 1986-12-27 | 1988-07-11 | Aichi Steel Works Ltd | Non-heattreated steel for hot forging |
-
1988
- 1988-09-27 JP JP24126588A patent/JPH0288748A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61238941A (en) * | 1985-04-15 | 1986-10-24 | Kobe Steel Ltd | Untempered steel for hot forging |
| JPS63111160A (en) * | 1986-10-30 | 1988-05-16 | Nkk Corp | High toughness non-heattreated steel for hot forging |
| JPS63166949A (en) * | 1986-12-27 | 1988-07-11 | Aichi Steel Works Ltd | Non-heattreated steel for hot forging |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5532723A (en) * | 1991-09-30 | 1996-07-02 | Rohm Co., Ltd. | Drive IC for a printing head |
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