JPH0474406B2 - - Google Patents
Info
- Publication number
- JPH0474406B2 JPH0474406B2 JP58075455A JP7545583A JPH0474406B2 JP H0474406 B2 JPH0474406 B2 JP H0474406B2 JP 58075455 A JP58075455 A JP 58075455A JP 7545583 A JP7545583 A JP 7545583A JP H0474406 B2 JPH0474406 B2 JP H0474406B2
- Authority
- JP
- Japan
- Prior art keywords
- strain
- variation
- heat treatment
- sintered
- alloy powder
- 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.)
- Expired
Links
- 229910045601 alloy Inorganic materials 0.000 claims description 19
- 239000000956 alloy Substances 0.000 claims description 19
- 239000000843 powder Substances 0.000 claims description 19
- 238000010438 heat treatment Methods 0.000 claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 9
- 239000002184 metal Substances 0.000 claims description 8
- 150000002739 metals Chemical class 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 239000002994 raw material Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 10
- 238000010791 quenching Methods 0.000 description 8
- 230000000171 quenching effect Effects 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 238000005255 carburizing Methods 0.000 description 5
- 238000005242 forging Methods 0.000 description 4
- 239000000314 lubricant Substances 0.000 description 4
- 238000003754 machining Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229910052758 niobium Inorganic materials 0.000 description 4
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 229910052720 vanadium Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000000996 additive effect Effects 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000005496 tempering Methods 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- -1 ferrous metals Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000007142 ring opening reaction Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
Description
本発明は鍛造後の熱処理で発生する歪のばらつ
きの少ない焼結鍛造部品に関するものである。
従来、焼結鍛造鋼では、Mn、Cr、Mo、Cu、
Niの中の２種以上の金属を含有する焼入れ性に
すぐれた合金粉末を用いて、これに潤滑剤として
のステアリン酸亜鉛及び黒煙粉などを所定の割合
に添加、混合し、密度6.0ないし7.2ｇ／cm3に圧粉
成形し、焼結後、熱間で鍛造してほゞ真密度に密
度を高め、更に熱処理などの後処理工程を行なつ
て焼結鍛造部品とするこゝろみがなされている。
しかるに上記焼結鋼では熱処理、特に焼入れ工
程または浸炭焼入れ工程で発生する熱処理歪のば
らつきが大きいため、部品として要求される寸法
精度内におさめることが困難であつた。そこで寸
法精度を高めるために、焼入れ工程または浸炭焼
入れ工程の後に、通常は更に焼戻し工程を経て機
械加工を行なつて補正しているが、製造コストの
上昇につながり、合金粉末の焼結鍛造部品への利
用の道を狭めているのが現状である。
本発明は上記の問題を解決するもので特殊な組
成の合金粉末を原料として製造される熱処理歪の
安定した焼結鍛造部品の提供を目的とするもので
ある。
本発明者は熱処理歪の発生原因について考究し
た結果、Nb、Al、Ｖ等の窒化物または炭化物形
成金属がオーステナイトの結晶成長を抑制する傾
向のあることに着目し、焼結鍛造用の合金粉末組
成に上記の金属の１種以上を添加して粗大粒子の
生成を防止することに想到し本発明を完成した。
すなわち、本発明の焼結鍛造部品は重量比で
Mn0.1〜0.9％、Cr0.1〜1.2％、Mo0.1〜0.8％、
Cu0.1〜2.0％、Ni0.1〜2.0％の金属のなかの２種
以上及びNb0.01〜0.4％、Al0.05〜0.1％、V0.02
〜0.15％のなかの１種以上を含有し、かつC0.03
〜0.4％、Si0.05％以下、残部鉄からなる合金粉末
を原料としてなることを特徴とするものである。
一般に焼結合金はMn、Cr、Mo等の鉄系金属
をそれぞれ数％、あるいは10％を越える比率で含
有しているが、焼結鍛造部品とする場合には空孔
部を有する一般的な焼結合金ほどの量を必要とし
ない。かえつて成形に困難を来たすことがあるの
で重量比にして0.1ないし数％の範囲が好ましい。
但し鍛造品の焼入れ性を高めるためには上記添加
金属を２種以上含有することが必要である。従つ
て本発明部品の原料としては重量比でMn0.1〜
0.9％、Cr0.1〜0.2％、Mo0.1〜0.8％、Cu0.1〜2.0
％、Ni0.1〜2.0％のなかの２種以上を含有する合
金組成を必要とする。添加する金属元素としては
後記の実施例に示すようにそれぞれNb0.01％、
Al0.005％、V0.02％以下では熱歪防止効果が少な
く、Nb0.4％、Al0.1％、V0.15％以上加えても期
待する程効果が増大せず、かえつて部品の強度を
低下させることになる。従つて各添加元素は重量
比でNb0.01〜0.4％、Al0.005〜0.1％、V0.02〜
0.15％の範囲が好ましい。
以下、本発明を実施例を用いて更に詳しく説明
する。
実施例 １
ほゞ一定の重量比組成で成分元素を含有する母
合金粉末に重量比を変えてNbを添加し第１表の
成分系とした合金粉末を使用して焼結鍛造部品を
製造し、熱処理歪のばらつきに対する影響を比較
した。
The present invention relates to a sintered forged part with less variation in distortion caused by heat treatment after forging. Conventionally, sintered forged steel contains Mn, Cr, Mo, Cu,
Using an alloy powder with excellent hardenability that contains two or more metals among Ni, zinc stearate as a lubricant, black smoke powder, etc. are added and mixed in a predetermined ratio to achieve a density of 6.0 or more. After compacting to 7.2g/cm 3 and sintering, hot forging to increase the density to almost true density, and then post-processing such as heat treatment to create sintered forged parts. It is being looked after. However, in the above-mentioned sintered steel, there are large variations in heat treatment distortion that occurs during heat treatment, particularly during the quenching process or the carburizing and quenching process, so it has been difficult to keep the dimensional accuracy within the required range for the parts. Therefore, in order to improve the dimensional accuracy, after the quenching or carburizing and quenching process, a further tempering process is usually performed and machining is performed to correct the dimensional accuracy, but this leads to an increase in manufacturing costs and sintered forged parts made of alloy powder. The current situation is narrowing the possibilities for its use. The present invention solves the above-mentioned problems, and aims to provide a sintered forged part with stable heat treatment distortion, which is manufactured using an alloy powder with a special composition as a raw material. As a result of investigating the causes of heat treatment distortion, the present inventor focused on the fact that nitride or carbide-forming metals such as Nb, Al, and V tend to suppress the crystal growth of austenite. The present invention was completed based on the idea of adding one or more of the above metals to the composition to prevent the formation of coarse particles. That is, the sintered forged parts of the present invention have a weight ratio of
Mn0.1~0.9%, Cr0.1~1.2%, Mo0.1~0.8%,
Two or more metals of Cu0.1~2.0%, Ni0.1~2.0%, Nb0.01~0.4%, Al0.05~0.1%, V0.02
Contains one or more of ~0.15% and C0.03
It is characterized by being made from an alloy powder consisting of ~0.4% Si, 0.05% Si or less, and the balance iron. Generally, sintered alloys contain ferrous metals such as Mn, Cr, and Mo in a ratio of a few percent or more than 10%, but when making sintered forged parts, common metals with pores are used. It does not require the same amount as sintered alloy. Since this may actually make molding difficult, it is preferably in the range of 0.1 to several percent by weight.
However, in order to improve the hardenability of the forged product, it is necessary to contain two or more of the above additive metals. Therefore, as a raw material for the parts of the present invention, the weight ratio of Mn is 0.1~
0.9%, Cr0.1~0.2%, Mo0.1~0.8%, Cu0.1~2.0
%, and 0.1 to 2.0% of Ni. The metal elements to be added include 0.01% Nb and 0.01% Nb, respectively, as shown in the examples below.
Below 0.005% Al and 0.02% V, the effect of preventing thermal strain is small, and even when adding 0.4% Nb, 0.1% Al, and 0.15% V or more, the effect does not increase as expected, and the strength of the parts is reduced. This will reduce the Therefore, each additive element has a weight ratio of Nb0.01~0.4%, Al0.005~0.1%, V0.02~
A range of 0.15% is preferred. Hereinafter, the present invention will be explained in more detail using Examples. Example 1 A sintered forged part was manufactured using an alloy powder having the component system shown in Table 1 by adding Nb at varying weight ratios to a master alloy powder containing component elements with a substantially constant weight ratio composition. , the influence on the variation of heat treatment strain was compared.
【表】
上記の成分系で粒度が60メツシユ以下の水噴霧
法で製造した合金粉末に、カーボン粉末及び潤滑
剤としてステアリン酸亜鉛をそれぞれ0.2％、0.6
％添加し、混合後、この粉末を密度6.5ｇ／c.c.に
成形し、AXガス中、1250℃で10分間加熱後、
1000℃にて熱間鍛造して真密度に密度を上昇せし
め直ちに油中で冷却した。次に窒素雰囲気中、
400℃で60分間焼戻し、所定の機械加工を行なつ
て第４図に示す内径d127mm、外径d244mm、リング
の開口巾a5mm、内外径の中心間の距離b7.5mm、厚
さ10mmのネービーＣリングを、各々の成分系につ
いて15個製造してテストピースとした。次にすべ
てのテストピースをRX雰囲気中、920℃で60分
間浸炭処理し、直ちに油焼入れした後、開口巾ａ
を測定して当初の値との差、すなわち熱処理歪を
測定し、テストピース間の歪のばらつきを算出
し、その結果を第１図に示した。
第１図から明らかなように0.01ないし0.4％の
重量比でNbを添加したテストピースでは未添加
の場合の歪のばらつきが3σで150μであるのに対
しNb含有量0.01％で80μとなり歪のばらつきを大
巾に低減していることがわかる。また0.4％を越
えても上記の効果の大巾な向上を望めず、かえつ
て酸化物が多くなり機械的特性、特に衝撃値を低
下させることが認められた。更にその他の成分系
の合金粉についての試験結果でも上記と同様の効
果が認められた。
実施例 ２
ほゞ一定の重量比組成で成分元素を含有する母
合金粉末に、重量比を変えてAlを添加し第２表
の成分系とした合金粉末を使用して焼結鍛造部品
を製造し、熱処理歪に対する影響を比較した。[Table] To the alloy powder manufactured by water spraying with the above component system and particle size of 60 mesh or less, carbon powder and zinc stearate as a lubricant are added at 0.2% and 0.6%, respectively.
After mixing, the powder was molded to a density of 6.5 g/cc, heated at 1250°C for 10 minutes in AX gas,
It was hot forged at 1000°C to increase the density to true density and immediately cooled in oil. Next, in a nitrogen atmosphere,
After tempering at 400℃ for 60 minutes and performing the specified machining, the inner diameter d 1 27 mm, outer diameter d 2 44 mm, ring opening width a 5 mm, distance between the centers of the inner and outer diameters b 7.5 mm, and the thickness shown in Figure 4 are obtained. Fifteen 10 mm navy C rings were manufactured for each component system and used as test pieces. Next, all test pieces were carburized in an RX atmosphere at 920℃ for 60 minutes, immediately oil quenched, and the opening width a
The difference from the initial value, that is, the heat treatment strain was measured, and the variation in strain between test pieces was calculated. The results are shown in FIG. As is clear from Figure 1, in the test pieces to which Nb was added at a weight ratio of 0.01 to 0.4%, the variation in strain was 150 μ at 3σ when no Nb was added, whereas it was 80 μ at 3σ with a Nb content of 0.01%. It can be seen that the variation is greatly reduced. Moreover, even if the content exceeds 0.4%, no significant improvement in the above-mentioned effects can be expected, and on the contrary, it has been found that the oxide content increases and the mechanical properties, particularly the impact value, decrease. Furthermore, the same effects as above were observed in test results for alloy powders of other component systems. Example 2 Sintered forged parts were manufactured using alloy powders with the composition shown in Table 2 by adding Al at varying weight ratios to a master alloy powder containing component elements with a substantially constant weight ratio composition. The effects on heat treatment distortion were then compared.
【表】
上記の成分系で粒度が60メツシユ以下の水噴霧
法で製造した合金粉末に、カーボン粉末及び潤滑
剤としてステアリン酸亜鉛をそれぞれ0.3％、0.6
％添加し、混合後、密度6.7ｇ／c.c.に圧粉成形し、
AXガス中、1150℃で20分間加熱後、1000℃にて
熱間鍛造して真密度に密度を上昇せしめ、直ちに
油中で冷却した。次にN2雰囲気中、400℃で60分
間焼戻し、所定の機械加工を行なつて、実施例１
と同一の寸法のネービーＣリングを各成分系につ
いて15個製造した。そして実施例１に準じて浸炭
焼入れ後のリングの開口巾ａを測定して歪のばら
つきを求めた。その結果第２図に示す如く、Al
の添加量0.005ないし0.1％で歪のばらつきを大巾
に低減し得ることを認めた。さらに他の成分系の
合金粉末の試験結果についても上記と同様の効果
が明らかとなつた。
実施例 ３
ほゞ一定量の重量比組成で成分元素を含有する
母合金に、重量比を変えてＶを添加し第３表の成
分系とした合金粉末を使用して焼結鍛造部品を製
造し、熱処理歪に対する影響を比較した。[Table] To the alloy powder produced by water spraying with the above component system and particle size of 60 mesh or less, carbon powder and zinc stearate as a lubricant are added at 0.3% and 0.6%, respectively.
% and after mixing, compacted to a density of 6.7g/cc,
After heating at 1150°C for 20 minutes in AX gas, hot forging at 1000°C to increase the density to true density, and immediately cooling in oil. Next, Example 1
Fifteen navy C rings with the same dimensions were manufactured for each component system. Then, according to Example 1, the opening width a of the ring after carburizing and quenching was measured to determine the variation in strain. As a result, as shown in Figure 2, Al
It was confirmed that the variation in strain can be significantly reduced by adding 0.005% to 0.1%. Furthermore, the same effects as those described above were revealed in test results for alloy powders of other component systems. Example 3 A sintered forged part was manufactured using an alloy powder with the composition shown in Table 3 by adding V at varying weight ratios to a master alloy containing component elements with a substantially constant weight ratio composition. The effects on heat treatment distortion were then compared.
【表】
上記の成分系で粒度が60メツシユ以下の水噴霧
法で製造した合金粉末にカーボン粉末及び潤滑剤
としてステアリン酸亜鉛をそれぞれ0.2％、0.6％
添加し、混合後、密度6.5ｇ／c.c.に粉末成形し、
AXガス中、1200℃で20分間加熱後、1000℃にて
熱間鍛造して真密度に密度を高め直ちに油中で冷
却した。次にN2雰囲気中、400℃で60分間焼戻
し、所定の機械加工を行ない実施例１と同一寸法
のネービーＣリングを各成分系について15個ずつ
製造した。
次に実施例１に準じて浸炭焼入れ前後のリング
の開口巾ａを測定して歪のばらつきを求めた結果
第３図に示す如くＶの添加量0.02ないし0.15％で
歪のばらつきを大巾に低減し得ることを認めた。
さらに他の成分系の合金粉末の試験結果について
も上記と同様の効果が明らかとなつた。
以下の実施例はすべてテストピース（ネービー
Ｃリング）による結果であるが、コネクテイング
ロツドや各種ギア等の部品に対しても同様の効果
が期待できる。
上記の如く本発明の焼結鍛造部品は、焼入れ工
程あるいは浸炭焼入れ工程において生ずる熱処理
歪のばらつきが少なくなつているため歪矯正のた
めの機械加工が不要となり製造コストを節減でき
る。このことは寸法精度公差の厳しい自動車用各
種ギアの製造コストの節減に著しい効果を発揮す
るものであり、さらに溶解材からの鍛造部品に比
較してもともと製造コストの安価な焼結鍛造部品
の用途を広く展開することができる。[Table] 0.2% and 0.6% of carbon powder and zinc stearate as a lubricant are added to the alloy powder manufactured by the water spray method with the above component system and a particle size of 60 mesh or less, respectively.
After adding and mixing, powder molding to a density of 6.5g/cc,
After heating at 1200°C for 20 minutes in AX gas, hot forging at 1000°C to increase the density to true density, and immediately cooling in oil. Next, it was tempered for 60 minutes at 400° C. in an N 2 atmosphere, and predetermined machining was performed to produce 15 navy C rings of each component system having the same dimensions as in Example 1. Next, according to Example 1, the opening width a of the ring before and after carburizing and quenching was measured to determine the variation in strain. As shown in Figure 3, the variation in strain was greatly reduced by adding V in an amount of 0.02 to 0.15%. It was acknowledged that this could be reduced.
Furthermore, the same effects as those described above were revealed in test results for alloy powders of other component systems. All of the following examples are results using a test piece (Navy C ring), but similar effects can be expected for parts such as connecting rods and various gears. As described above, the sintered and forged parts of the present invention have less variation in heat treatment strain caused during the quenching process or the carburizing and quenching process, so machining for strain correction is not required, and manufacturing costs can be reduced. This has a significant effect on reducing the manufacturing cost of various automotive gears that have strict dimensional accuracy tolerances, and furthermore, it is possible to use sintered forged parts, which are originally cheaper to manufacture than parts forged from melted materials. can be widely deployed.
第１図は実施例１のNb添加量と歪のばらつき
との関係を示すグラフを表わし、第２図は実施例
２のAl添加量と歪のばらつきとの関係を示すグ
ラフを表わし、第３図は実施例３のＶ添加量と歪
のばらつきとの関係を示すグラフを表わし、第４
図はネービーＣリングの平面図を表わす。
FIG. 1 shows a graph showing the relationship between the Nb addition amount and strain variation in Example 1, FIG. 2 shows a graph showing the relationship between Al addition amount and strain variation in Example 2, and FIG. The figure shows a graph showing the relationship between the amount of V added and the variation in strain in Example 3.
The figure represents a plan view of the navy C-ring.
Claims (1)
Mo0.1〜0.8％、Cu0.1〜2.0％、Ni0.1〜2.0％の金
属のなかの２種以上及びNb0.01〜0.4％、Al0.005
〜0.1％、V0.02〜0.15％のなかの１種以上を含有
し、かつC0.03〜0.4％、Si0.05％以下、残部鉄か
らなる合金粉末を原料としてなることを特徴とす
る熱処理歪の安定した焼結鍛造部品。1 Mn0.1-0.9%, Cr0.1-0.2% by weight,
Two or more metals of Mo0.1~0.8%, Cu0.1~2.0%, Ni0.1~2.0%, Nb0.01~0.4%, Al0.005
-0.1%, V0.02-0.15%, and a heat treatment characterized by using as a raw material an alloy powder consisting of C0.03-0.4%, Si0.05% or less, and the balance iron. Sintered forged parts with stable distortion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58075455A JPS59200740A (en) | 1983-04-28 | 1983-04-28 | Sintered and forged parts in which strain by heat treatment is stabilized |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58075455A JPS59200740A (en) | 1983-04-28 | 1983-04-28 | Sintered and forged parts in which strain by heat treatment is stabilized |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59200740A JPS59200740A (en) | 1984-11-14 |
| JPH0474406B2 true JPH0474406B2 (en) | 1992-11-26 |
Family
ID=13576772
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58075455A Granted JPS59200740A (en) | 1983-04-28 | 1983-04-28 | Sintered and forged parts in which strain by heat treatment is stabilized |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59200740A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT382334B (en) * | 1985-04-30 | 1987-02-10 | Miba Sintermetall Ag | CAMS FOR SHRINKING ON A CAMSHAFT AND METHOD FOR PRODUCING SUCH A CAM BY SINTERING |
| JP2612072B2 (en) * | 1989-08-31 | 1997-05-21 | 日立粉末冶金株式会社 | Cylindrical iron-based sintered slag for plastic working and method for producing the same |
-
1983
- 1983-04-28 JP JP58075455A patent/JPS59200740A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59200740A (en) | 1984-11-14 |
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