JPS62187536A - Manufacture of non-refining forgings - Google Patents
Manufacture of non-refining forgingsInfo
- Publication number
- JPS62187536A JPS62187536A JP2765686A JP2765686A JPS62187536A JP S62187536 A JPS62187536 A JP S62187536A JP 2765686 A JP2765686 A JP 2765686A JP 2765686 A JP2765686 A JP 2765686A JP S62187536 A JPS62187536 A JP S62187536A
- Authority
- JP
- Japan
- Prior art keywords
- forging
- steel
- refining
- toughness
- thereafter
- 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
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- 238000005242 forging Methods 0.000 title abstract description 36
- 238000007670 refining Methods 0.000 title abstract description 6
- 229910000851 Alloy steel Inorganic materials 0.000 claims abstract description 4
- 229910000746 Structural steel Inorganic materials 0.000 claims description 2
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 abstract description 14
- 239000010959 steel Substances 0.000 abstract description 14
- 238000010438 heat treatment Methods 0.000 abstract description 10
- 239000010410 layer Substances 0.000 abstract description 10
- 238000001816 cooling Methods 0.000 abstract description 7
- 238000005098 hot rolling Methods 0.000 abstract description 7
- 238000010791 quenching Methods 0.000 abstract description 7
- 239000002344 surface layer Substances 0.000 abstract description 6
- 230000000171 quenching effect Effects 0.000 abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 3
- 229910000859 α-Fe Inorganic materials 0.000 abstract description 3
- 229910001562 pearlite Inorganic materials 0.000 abstract description 2
- 238000010521 absorption reaction Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 15
- 238000005096 rolling process Methods 0.000 description 9
- 230000000694 effects Effects 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- 229910001566 austenite Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 241000446313 Lamella Species 0.000 description 1
- 101100202505 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) SCM4 gene Proteins 0.000 description 1
- 229910001035 Soft ferrite Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009661 fatigue test Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
Landscapes
- Forging (AREA)
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は鍛造後、非調質のままで疲労強度および靭性に
優れたゼルトおよびシャフト類の製造方法に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing selts and shafts that remain unheated after forging and have excellent fatigue strength and toughness.
(従来の技術)
従来、自動車および産業機械用に使用されるゼルトおよ
びシャフト等疲労強度および靭性が必要とされる部品の
加工は、鍛造時の変形能および変形抵抗の点から、主と
して熱間で行なわれていた。(Prior art) Traditionally, parts that require high fatigue strength and toughness, such as bolts and shafts used for automobiles and industrial machinery, have been processed mainly by hot processing in terms of deformability and deformation resistance during forging. It was being done.
しかしこの熱間鍛造は1200℃以上の高温度に加熱し
て行なわれるため、オーステナイト結晶粒が成長粗大化
し、靭性が著しく低下する。このため鍛造後に材質改善
のための焼入焼戻等の熱処理が不可欠であった。However, since this hot forging is performed by heating to a high temperature of 1200° C. or higher, austenite crystal grains grow and become coarser, resulting in a significant decrease in toughness. For this reason, heat treatment such as quenching and tempering was essential to improve the material quality after forging.
このように、熱間鍛造による成形加工の場合には、鍛造
前の高温加熱および鍛造品の調質処理のため多大なエネ
ルギーを要し、また寸法精度が悪く、鍛造後に切削加工
をしなければならないため、歩留りも低かった。In this way, in the case of forming by hot forging, a large amount of energy is required for high-temperature heating before forging and heat treatment of the forged product, and the dimensional accuracy is poor, so cutting must be performed after forging. As a result, the yield was low.
これに対して、鍛造後の非調質化および切削工程の省略
等を目的として、圧延後急冷し、その後熱間鍛造に比較
して加工温度の低い温間域で鍛造する温間鍛造法が、例
えば特開昭58−77526号公報に開示されている。On the other hand, for the purpose of non-heat refining after forging and omitting the cutting process, there is a warm forging method that involves rapid cooling after rolling and then forging in a warm region with a lower processing temperature than hot forging. , for example, is disclosed in Japanese Patent Application Laid-Open No. 58-77526.
しかし、この方法は素材を内部まで冷却するため、多量
の冷媒および冷却に多くの時間を要し、さらに鍛造時の
変形抵抗が大きく工具の寿命が著しく悪い等の欠点を有
していた。However, since this method cools the material to the inside, it requires a large amount of refrigerant and a long time for cooling, and has the disadvantages that the deformation resistance during forging is large and the life of the tool is significantly shortened.
(本発明が解決しようとする問題点)
このように、従来の鍛造品の製造技術は鍛造後焼入焼戻
等の調質処理が必要であったシ、あるいは調質処理が必
要でない場合においても成形時の変形抵抗が大きく工具
寿命が著しく劣化する等の欠点を有していた。(Problems to be Solved by the Present Invention) As described above, conventional forged product manufacturing technology requires heat treatment such as quenching and tempering after forging, or in cases where heat treatment is not required. However, the deformation resistance during molding was large and the tool life was significantly reduced.
(問題点を解決するための手段、作用)本発明の要旨と
するところは、機械構造用鋼または低合金鋼を熱間圧延
後急冷し、表面に断面面積率で20〜70%の焼入深さ
層を生成させ、その後550℃〜Ac1点間で鍛造を行
なうことを特徴とする、引張強度70Kgf/mm2以
上および常温でのシャルピー吸収エネルギーが5 Kg
fm以上を有する非調質鍛造品の製造方法である。(Means and effects for solving the problems) The gist of the present invention is to rapidly cool mechanical structural steel or low alloy steel after hot rolling, and harden the surface by 20 to 70% in cross-sectional area ratio. A tensile strength of 70Kgf/mm2 or more and a Charpy absorbed energy of 5Kg at room temperature, characterized by forming a deep layer and then forging between 550℃ and one point of Ac.
This is a method for manufacturing a non-thermal forged product having fm or more.
本発明は、熱間圧延後比較的少ない水量で短時間の冷却
によシ表面層のみを急冷して焼入組織とし、内部は軟質
のフェライトおよびパーライト組織のままとするので、
これによって弯形抵抗が低く、また変形能に優れた棒鋼
が得られ、温間鍛造が可能となる。このため切削工程も
必要でなく、しかも鍛造後の調質処理を省略しても疲労
強度および靭性に優れた鍛造品が得られる。In the present invention, after hot rolling, only the surface layer is rapidly cooled to a quenched structure by cooling in a short time with a relatively small amount of water, while the inside remains a soft ferrite and pearlite structure.
As a result, a steel bar with low curvature resistance and excellent deformability can be obtained, and warm forging becomes possible. Therefore, a cutting process is not necessary, and a forged product with excellent fatigue strength and toughness can be obtained even if heat treatment after forging is omitted.
次に本発明において各要件を限定した理由について述べ
る。Next, the reason for limiting each requirement in the present invention will be described.
先ず本発明の対象鋼種であるが、自動車および産業機械
等に使用される通常の機械構造用鋼または低合金鋼の範
中に属するものであれば特に制限はない。望ましい成分
範囲を簡単に述べる。First, there are no particular restrictions on the steel types to which the present invention applies, as long as they fall within the range of ordinary mechanical structural steels or low alloy steels used in automobiles, industrial machinery, etc. Briefly describe the desired range of ingredients.
■ C: 0.30〜0.60%、Cは焼入性の高い元
素であり、鍛造品の強度を大きく左右し、0.30%未
満では引張強度として70 Kgf /mjが得られな
い場合があシ、また0、60%を越えると強度が高く成
シすぎ、所定の靭性が得られないからである。■ C: 0.30-0.60%, C is an element with high hardenability and greatly affects the strength of forged products, and if it is less than 0.30%, a tensile strength of 70 Kgf / mj cannot be obtained. Moreover, if the content exceeds 0.60%, the strength will be too high and the desired toughness will not be obtained.
■ St : 0.10〜0.50%。Stは脱酸作用
を有し、このためには最低限0.10%以上必要である
。しかし0.50%を越えると特にフェライトが脆化し
、所定の靭性が得られない。■ St: 0.10-0.50%. St has a deoxidizing effect, and for this purpose, a minimum amount of 0.10% or more is required. However, if it exceeds 0.50%, the ferrite in particular becomes brittle and the desired toughness cannot be obtained.
■ Mn : 0.30〜2.00%。MnはStと同
様に脱酸作用を有し、Mnのみで脱酸する場合には最低
限0.30%以上必要である。また、Mnは比較的靭性
劣化の少ない焼入性向上元素として用いるが、2.00
%を越えるとコスト高となる。■Mn: 0.30-2.00%. Like St, Mn has a deoxidizing effect, and when deoxidizing with Mn alone, a minimum amount of 0.30% or more is required. In addition, Mn is used as an element for improving hardenability with relatively little deterioration of toughness.
If it exceeds %, the cost will be high.
■ Cr : 2.00%以下。Crは焼入性向上元素
であると同時に、内部に生成するノぞ−ライトのラメラ
間隔を粗くすることによって鍛造時の変形抵抗を低減す
るが、2.00%を越えるとコスト高となる。■ Cr: 2.00% or less. Cr is an element that improves hardenability and at the same time reduces the deformation resistance during forging by roughening the lamella spacing of the nozorite formed inside, but if it exceeds 2.00%, the cost increases.
■ Ni:5.Q%以下。Niはフェライトの強度およ
び靭性の両方を高めるが、上限はコストの点から制限さ
れる。■ Ni:5. Q% or less. Ni increases both the strength and toughness of ferrite, but the upper limit is limited by cost.
■ B : 0.0005〜0.0050%。Bは少量
で著しく焼入性を高める元素であるが、0.0005%
未満ではその効果がなく、また0、0050%を越える
と靭延性が劣化する。■ B: 0.0005-0.0050%. B is an element that significantly improves hardenability in small amounts, but at 0.0005%
If it is less than 0.005%, there is no effect, and if it exceeds 0.0050%, toughness and ductility deteriorate.
次に、表面焼入層の深さを断面面積率で20〜70%に
限定した理由について述べる。一般にシャフト等の疲労
強度を高める方法としては、これら部品を成形加工後に
高周波等によシ表面層を焼入し、数%の硬化層を生成さ
せる方法がとられている。本発明は温間鍛造後非調質の
ままで疲労強度を高める方法として、熱間圧延後の急冷
によって表面部に焼入層を生成させるもので、この硬さ
および組織を、温間鍛造後も残存するような条件で鍛造
を行なうようにしたものである。焼入深さ層が20%未
満の場合には鍛造品の疲労強度は十分でなく、また70
%を越えると鍛造時の変形抵抗が増大して工具寿命が劣
化するからである(ここではマルテンサイト組織が50
%以上となっている部分を焼入深さ層とする。)。Next, the reason why the depth of the surface hardening layer is limited to 20 to 70% in cross-sectional area ratio will be described. In general, a method for increasing the fatigue strength of shafts and the like is to harden the surface layer of these parts by high-frequency waves or the like after forming them, thereby producing a hardened layer of several percent. The present invention is a method for increasing fatigue strength without heat-refining after warm forging, in which a hardened layer is generated on the surface by rapid cooling after hot rolling. The forging was carried out under conditions such that the remaining If the quench depth layer is less than 20%, the fatigue strength of the forged product will not be sufficient;
This is because if the martensitic structure exceeds 50%, the deformation resistance during forging increases and the tool life deteriorates.
% or more is defined as the hardened depth layer. ).
また、鍛造の下限温度を550℃としたのは、550℃
未満では変形抵抗の増大および靭延性が低下するからで
ある。さらに、鍛造温度の上限をAc1点としたのは、
Ac 1点を越えると表面部が再度オーステナイト化し
て、熱間圧延において作シ込んだ表面層の硬度および焼
入組織が消滅するからである。In addition, the lower limit temperature for forging was set at 550°C.
This is because if it is less than that, the deformation resistance will increase and the toughness and ductility will decrease. Furthermore, the upper limit of the forging temperature was set to Ac1 point because
This is because when the Ac value exceeds 1 point, the surface portion becomes austenite again, and the hardness and hardened structure of the surface layer indented during hot rolling disappear.
(実施例) 次に、本発明の実施例について述べる。(Example) Next, examples of the present invention will be described.
表1に供試材の種類および化学成分を示す。供試材とし
て機械構造用炭素鋼(S53C)および低合金鋼(80
M440,5AE15B36 )に適合する化学成分の
120謂中ビレツトを用いた。Table 1 shows the types and chemical components of the test materials. Carbon steel for mechanical structures (S53C) and low alloy steel (80
A billet with chemical components compatible with M440,5AE15B36) was used.
各供試材ビレットはいずれも1000〜1050℃に加
熱し30IaIφの棒鋼に圧延した。このときの仕上げ
圧延温度は表2(記号A、 B、 C,E、 F、 G
。Each sample billet was heated to 1000 to 1050°C and rolled into a 30IaIφ steel bar. The finish rolling temperatures at this time are shown in Table 2 (symbols A, B, C, E, F, G
.
I、 G、 K )に示す通シで、圧延後345 rr
?/ hr(553C)および210 vl/ hr
(80M440 および5AE15B36 )の水量で
5秒間冷却し、又、同時に比較材として表2(記号り、
H,N )に示す仕上げ温度から空冷して製造した。I, G, K), 345 rr after rolling.
? /hr (553C) and 210 vl/hr
(80M440 and 5AE15B36) for 5 seconds, and at the same time as comparative materials Table 2 (symbols,
It was manufactured by air cooling from the finishing temperature shown in (H,N).
第1図に、553Cについて745℃の仕上げ温度で終
了し、圧延後冷却した場合(表2中の記号C)の横断面
の硬度分布を示す。同図から明らかな如く、棒鋼の中心
部に近くなるに従って硬度は低下しておシ、この場合の
焼入深さ層は64.0%である。FIG. 1 shows the hardness distribution in the cross section of 553C when the rolling was completed at a finishing temperature of 745° C. and cooled after rolling (symbol C in Table 2). As is clear from the figure, the hardness decreases closer to the center of the steel bar, and the quenched depth layer in this case is 64.0%.
次に、このようにして製造した棒鋼の温間鍛造後の材質
特性を調査するため、30Wφ×55〇−長さの棒鋼を
鍛造温度600℃および700℃(553C,SCM4
40.および5AE15B36のAc1点はそれぞれ7
25℃、744℃および710℃であ[、Ac1点直下
の鍛造に相当する)において11.2 ms厚さまで鍛
造した。このようにして温間鍛造した鍛造材からJIS
1号回転曲げ用疲れ試験片、6φX32Lの小型引張
試験片、およびJIS S号シャルピー衝撃試験片を
採集し、それぞれの試験に共した。この場合、圧延後水
冷を行なった本発明材については特別の熱処理を行なわ
ず非調質のままで、また、圧延後空冷した比較材につい
ては鍛造後850℃で焼入し、600℃で焼戻処理を行
なった後で上記試験片を採取した。Next, in order to investigate the material properties of the steel bars produced in this way after warm forging, we used 30Wφ x 550-length steel bars at forging temperatures of 600°C and 700°C (553C, SCM4
40. and Ac1 point of 5AE15B36 is 7 respectively.
It was forged to a thickness of 11.2 ms at 25°C, 744°C and 710°C [corresponding to forging just below the Ac1 point]. From the forged material warm-forged in this way, JIS
A No. 1 rotary bending fatigue test piece, a 6φ x 32L small tensile test piece, and a JIS No. S Charpy impact test piece were collected and used in each test. In this case, the material of the present invention, which was water-cooled after rolling, remained unheated without any special heat treatment, and the comparative material, which was air-cooled after rolling, was quenched at 850°C after forging and quenched at 600°C. The above test piece was taken after the back treatment.
それぞれの試験片は主として中心部から採取したが、5
530鋼の本発明材で表2、記号Cの600℃鍛造材に
ついては、疲れおよびシャルピー衝撃試験片を表層部か
ら本採取し、試験を行なった。Each specimen was mainly taken from the center, but 5
Regarding the 600° C. forged material of the present invention made of 530 steel and symbol C in Table 2, fatigue and Charpy impact test pieces were taken from the surface layer and tested.
表2にこれら中心部から採取した試験による疲労および
引張強度、および靭性の調査結果を示す。Table 2 shows the results of tests on fatigue, tensile strength, and toughness taken from these central areas.
仕上圧延後水冷を行ない、600℃で温間鍛造を行なっ
たものの疲労および引張強度は、温間鍛造後焼入焼戻処
理を行なったものに比較してはるかに高い。また、AC
1点近傍の700℃で温間鍛造を行なった場合の疲労お
よび引張強度は若干低く々るが、それでも疲労強度は3
5キロ、!た引張強度については70キロのレベルにあ
る。またシャル四吸収エネルギーは600℃で温間鍛造
を行なったものでは、温間鍛造後の熱処理材に比較して
若干劣っているが、それでも5キロのレベルにあF)、
700C温間鍛造材では熱処理材と同等以上の高い値が
得られている。!た、553C鋼の本発明材で記号Cの
600℃鍛造材の表層部試験片による疲労強度は55K
gf/−1および吸収エネルギーは9 Kgfmであっ
た。The fatigue and tensile strength of the specimens subjected to water cooling after finishing rolling and warm forging at 600° C. are much higher than those of the specimens subjected to quenching and tempering after warm forging. Also, AC
Fatigue and tensile strength are slightly lower when warm forging is performed at 700°C near the 1st point, but fatigue strength is still 3.
5 km! The tensile strength is at the level of 70 kg. In addition, the absorbed energy of the material warmly forged at 600℃ is slightly inferior to that of the heat-treated material after warm forging, but it is still at the level of 5kg.
The 700C warm forged material has a high value equivalent to or higher than that of the heat-treated material. ! In addition, the fatigue strength of the surface layer test piece of 600℃ forged material of 553C steel of the present invention with symbol C is 55K.
gf/-1 and absorbed energy was 9 Kgfm.
(発明の効果)
このように、本発明は熱間圧延後鋼材を急冷して表面部
に硬い焼入層を生成させることによって、その後の熱処
理を省略しても、疲労強度および靭性の優れた鍛造品を
製造することのできる方法で、その効果は大きい。(Effects of the Invention) As described above, the present invention rapidly cools the steel material after hot rolling to generate a hard hardened layer on the surface, thereby achieving excellent fatigue strength and toughness even if the subsequent heat treatment is omitted. This is a method that can produce forged products, and its effects are great.
第1図合は圧延後急冷を行なったS53C30wφ棒鋼
の横断面硬度分布を示す図である。
代理人 弁理士 秋 沢 政 光
他2名The first figure is a diagram showing the cross-sectional hardness distribution of an S53C30wφ steel bar that was rapidly cooled after rolling. Agent: Patent attorney Masamitsu Akizawa and 2 others
Claims (1)
、表面に断面面積率で20〜70%の焼入深さ層を生成
させ、その後550℃〜Ac_1点間で鍛造を行なうこ
とを特徴とする、引張強度70Kgf/mm^2以上お
よび常温でのシャルピー吸収エネルギー5Kgfm以上
を有する非調質鍛造品の製造方法。(1) Machine structural steel or low alloy steel is hot-rolled and then rapidly cooled to form a hardened depth layer with a cross-sectional area ratio of 20 to 70% on the surface, and then forged between 550℃ and Ac_1 point. A method for producing a non-thermal forged product having a tensile strength of 70 Kgf/mm^2 or more and a Charpy absorbed energy of 5 Kgfm or more at room temperature, characterized in that:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2765686A JPS62187536A (en) | 1986-02-10 | 1986-02-10 | Manufacture of non-refining forgings |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2765686A JPS62187536A (en) | 1986-02-10 | 1986-02-10 | Manufacture of non-refining forgings |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS62187536A true JPS62187536A (en) | 1987-08-15 |
Family
ID=12226970
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2765686A Pending JPS62187536A (en) | 1986-02-10 | 1986-02-10 | Manufacture of non-refining forgings |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS62187536A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011080794A1 (en) * | 2009-12-28 | 2011-07-07 | アルファナテクノロジー株式会社 | Method of manufacturing rotary device and rotary device manufactured by the same |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5877526A (en) * | 1981-10-31 | 1983-05-10 | Sumitomo Metal Ind Ltd | Production of unnormalized high-strength forging |
-
1986
- 1986-02-10 JP JP2765686A patent/JPS62187536A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5877526A (en) * | 1981-10-31 | 1983-05-10 | Sumitomo Metal Ind Ltd | Production of unnormalized high-strength forging |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011080794A1 (en) * | 2009-12-28 | 2011-07-07 | アルファナテクノロジー株式会社 | Method of manufacturing rotary device and rotary device manufactured by the same |
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