JPH02274801A - Finishing reduction method for alloy steel powder - Google Patents
Finishing reduction method for alloy steel powderInfo
- Publication number
- JPH02274801A JPH02274801A JP1096986A JP9698689A JPH02274801A JP H02274801 A JPH02274801 A JP H02274801A JP 1096986 A JP1096986 A JP 1096986A JP 9698689 A JP9698689 A JP 9698689A JP H02274801 A JPH02274801 A JP H02274801A
- Authority
- JP
- Japan
- Prior art keywords
- cooling
- alloy steel
- steel powder
- reduction
- 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.)
- Granted
Links
- 239000000843 powder Substances 0.000 title claims abstract description 44
- 238000000034 method Methods 0.000 title claims abstract description 24
- 229910000851 Alloy steel Inorganic materials 0.000 title claims abstract description 13
- 238000001816 cooling Methods 0.000 claims abstract description 66
- 230000001590 oxidative effect Effects 0.000 claims abstract description 19
- 238000000137 annealing Methods 0.000 claims abstract description 15
- 239000001257 hydrogen Substances 0.000 claims abstract description 12
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 12
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 7
- 239000002994 raw material Substances 0.000 claims abstract description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 229910000831 Steel Inorganic materials 0.000 abstract description 10
- 239000010959 steel Substances 0.000 abstract description 10
- 229910052804 chromium Inorganic materials 0.000 abstract description 4
- 229910000979 O alloy Inorganic materials 0.000 abstract description 3
- 238000004519 manufacturing process Methods 0.000 abstract description 2
- 150000002431 hydrogen Chemical class 0.000 abstract 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 11
- 238000007796 conventional method Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000010583 slow cooling Methods 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000001739 density measurement Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 230000002265 prevention 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
- 238000004904 shortening Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、Crおよび炭素を予合金化させたアトマイズ
鉄粉などを原料とし、これを仕上還元焼鈍することによ
り、低酸素合金鋼粉を得るための還元焼鈍後の新規な冷
却方法に関する。[Detailed Description of the Invention] <Industrial Application Field> The present invention uses atomized iron powder prealloyed with Cr and carbon as a raw material and performs finish reduction annealing to produce low oxygen alloy steel powder. It relates to a novel cooling method after reduction annealing for obtaining.
〈従来の技術〉
鉄粉焼結部品の需要は年々増加の一途をたどってきたが
、近年その傾向は鈍フてきた。<Conventional Technology> The demand for iron powder sintered parts has been increasing year by year, but the trend has slowed down in recent years.
しかしながら、高強度、高靭性が要求される部品に対応
した合金鋼粉は需要が増大する傾向にある。 強化合金
元素としては安価なMn、Crが適している。 しかし
Mn、Crを予合金化した銅粉を従来法の水アトマイズ
−ガス還元法で製造すると、これらの元素は酸素との親
和力が強いために銅粉中のO量を低減することが困難で
あった。 そこでこのようなMn。However, demand for alloy steel powder suitable for parts requiring high strength and high toughness is increasing. Cheap Mn and Cr are suitable as reinforcing alloy elements. However, when copper powder prealloyed with Mn and Cr is produced using the conventional water atomization-gas reduction method, it is difficult to reduce the amount of O in the copper powder because these elements have a strong affinity for oxygen. there were. Therefore, such Mn.
Crを含む合金鋼粉の脱酸を行う方法として真空還元法
が提案され(特開昭61−19004および63−73
01参照)、現在低酸素鋼粉が製造されている。A vacuum reduction method was proposed as a method for deoxidizing alloy steel powder containing Cr (Japanese Patent Laid-Open Nos. 61-19004 and 1983-73).
01), low-oxygen steel powder is currently being produced.
これらの提案に係る熱処理炉はCrおよび炭素を含む原
料粉末を予熱、乾燥するための予熱室、予熱後の原料粉
末を含有炭素の利用により脱酸し、焼鈍する段階の還元
焼鈍室および還元焼鈍粉末を冷却するための冷却室に区
画されている。 これらは横並びに連続配置され、それ
ら各室の境界にはそれぞれ可動扉が設けられ、各室が独
立した空間となるように構成されている。 それら各室
にはそれぞれ減圧用排気装置を設けた構成によってなる
金属粉末の還元焼鈍炉である。The heat treatment furnace according to these proposals includes a preheating chamber for preheating and drying the raw material powder containing Cr and carbon, a reduction annealing chamber and a reduction annealing stage in which the raw material powder after preheating is deoxidized by using the carbon contained and annealed. It is divided into a cooling chamber for cooling the powder. These rooms are arranged side by side in series, with movable doors provided at the boundaries of each room, so that each room becomes an independent space. This is a metal powder reduction annealing furnace configured such that each chamber is provided with an exhaust device for depressurization.
また特開昭63−7301においては還元焼鈍後の粉を
冷却室において非酸化性雰囲気中で圧縮性に影響を及ぼ
さない800℃までファンを回転させて急冷を行い、次
に同じ非酸化性雰囲気中で20 Torr、以下まで真
空ポンプにより減圧を行い、400℃までの間は250
℃/hr以下の冷却速度で徐冷を行い、最後に圧縮性に
影響を及ぼさない400℃〜室温まで非酸化性雰囲気中
でファンを回転させて急冷処理を行う技術が開示されて
いる。In addition, in JP-A-63-7301, powder after reduction annealing is rapidly cooled in a non-oxidizing atmosphere in a cooling chamber by rotating a fan to 800°C, which does not affect compressibility, and then in the same non-oxidizing atmosphere. Inside, the pressure is reduced to 20 Torr or less using a vacuum pump, and the pressure is reduced to 250 Torr up to 400°C.
A technique has been disclosed in which slow cooling is performed at a cooling rate of .degree. C./hr or less, and finally quenching is performed by rotating a fan in a non-oxidizing atmosphere from 400.degree. C. to room temperature, which does not affect compressibility.
一方、銅粉の圧縮性を支配する冷却時の冶金的要因は銅
粉内部に存在する結晶粒の大きさである。 この結晶を
粗大化させれば結晶粒界の周長が大となって粉末冶金法
による圧縮成形時に塑性変形を起し易くなり、その結果
として圧縮性の良好な銅粉を得ることができる。On the other hand, the metallurgical factor during cooling that governs the compressibility of copper powder is the size of crystal grains present inside the copper powder. If these crystals are coarsened, the circumference of the grain boundaries becomes large, making it easier for plastic deformation to occur during compression molding by powder metallurgy, and as a result, copper powder with good compressibility can be obtained.
〈発明が解決しようとする課題〉
この還元焼鈍炉を用い還元焼鈍後の鋼粉を冷却室中の非
酸化性雰囲気下で自然冷却すると、その冷却に長時間を
必要とし、予熱−還元焼鈍−冷却工程のうち冷却段階が
律速となり、生産性低下を招く。<Problems to be Solved by the Invention> When steel powder after reduction annealing is naturally cooled in a non-oxidizing atmosphere in a cooling chamber using this reduction annealing furnace, a long time is required for cooling, and the preheating, reduction annealing, and The cooling stage of the cooling process becomes rate-limiting, leading to a decrease in productivity.
また、特開昭63−7301に基く冷却方法によると途
中で冷却速度を急激に変化させるため金属粉末をトレイ
に充填した際の充填層表面部と中心部の性状にバラツキ
を生じて品質低下を招く問題点を抱えていた。Furthermore, according to the cooling method based on JP-A No. 63-7301, the cooling rate changes rapidly during the process, which causes variations in the properties of the surface and center of the packed layer when the tray is filled with metal powder, resulting in quality deterioration. It had some problems.
そこで本発明の目的は、l)圧縮性が高く、2)冷却時
間の短縮を図って生産性を向上させると共に、3)充填
層表面部と中心部が均一な品質になる銅粉を製造するの
に好適な金属粉未還元焼鈍後の冷却方法を提案するとこ
ろにある。Therefore, the purpose of the present invention is to produce copper powder that (1) has high compressibility, (2) improves productivity by shortening cooling time, and (3) has uniform quality on the surface and center of the packed bed. The purpose is to propose a cooling method after non-reduced annealing of metal powder suitable for.
〈課題を解決するための手段〉
すなわち、本発明は、Crおよび炭素を含むアトマイズ
された合金鋼粉用原料粉末を減圧雰囲気中で800℃〜
1300℃の還元温度で仕上還元焼鈍し、引き続いて冷
却するに際して、前記仕上還元温度から800℃までの
間を非酸化性雰囲気中で800℃/ h r以上の速度
で冷却し、その後800℃〜300℃までの間を水素雰
囲気中で280〜b
冷却し、さらに300℃以下を非酸化性雰囲気中で80
0℃/ h r以上の速度で冷却するととを特徴とする
合金銅粉の仕上還元方法を提供するものである。<Means for Solving the Problem> That is, the present invention provides a method for heating raw material powder for atomized alloy steel powder containing Cr and carbon at 800°C to 800°C in a reduced pressure atmosphere.
Final reduction annealing is performed at a reduction temperature of 1300°C, and during subsequent cooling, cooling is performed at a rate of 800°C/hr or more in a non-oxidizing atmosphere from the final reduction temperature to 800°C, and then from 800°C to 800°C. Cool to 300°C in a hydrogen atmosphere at 280°C to 80°C in a non-oxidizing atmosphere.
The present invention provides a method for finishing reduction of alloyed copper powder, which is characterized by cooling at a rate of 0° C./hr or more.
以下に本発明をさらに詳細に説明する。The present invention will be explained in more detail below.
本発明はCr系合金鋼粉の仕上還元後の冷却方法に関す
るものである。The present invention relates to a method for cooling Cr-based alloy steel powder after finishing reduction.
従来では仕上還元後の粉末は冷却室において非酸化性雰
囲気中で圧縮性に影響を及ぼさない800℃までファン
を回転させ、急冷を行う。Conventionally, the powder after final reduction is rapidly cooled in a non-oxidizing atmosphere in a cooling chamber by rotating a fan to a temperature of 800° C. which does not affect compressibility.
次に同じ非酸化性雰囲気中20 Torr、以下まで真
空ポンプによる減圧を行い、400℃までの間は250
℃/ h r以下の冷却速度で徐冷を行い、最後に圧縮
性に影響を及ぼさない400℃〜室温まで非酸化性雰囲
気中でファンを回転させ急冷処理を行っているのは前述
の通りである。Next, in the same non-oxidizing atmosphere, the pressure was reduced to 20 Torr or less using a vacuum pump, and the pressure was reduced to 250 Torr up to 400°C.
As mentioned above, slow cooling is performed at a cooling rate of ℃/hr or less, and finally, a rapid cooling process is performed by rotating a fan in a non-oxidizing atmosphere from 400℃ to room temperature, which does not affect compressibility. be.
本発明はこの20 Torr、以下の減圧状態で400
℃まで徐冷する区間を減圧せずに水素中で徐冷するので
より低い温度状態(300℃)まで従来(冷却速度25
0℃/ h r以下)より短い冷却時間(冷却速度28
0℃〜600℃/hr)で圧縮性が向上できることを見
い出してなされたものである。The present invention is designed to operate at a reduced pressure of 20 Torr or less at a pressure of 400 Torr or less.
Since the section where the temperature is slowly cooled down to 300°C is slowly cooled in hydrogen without reducing the pressure, it is possible to reach a lower temperature state (300°C) than before (cooling rate 25°C).
0℃/hr or less), shorter cooling time (cooling rate 28
This was done after discovering that the compressibility can be improved at a temperature of 0°C to 600°C/hr).
本発明において、仕上還元焼鈍は、800℃以下では還
元が不完全であり、1300℃以上では焼結が進むため
800℃〜1300℃の間で行う。 このとき20 T
orr、以下の減圧雰囲気中で還元を行なう。In the present invention, the final reduction annealing is performed at a temperature of 800°C to 1300°C because reduction is incomplete at temperatures below 800°C and sintering progresses at temperatures above 1300°C. At this time 20 T
The reduction is carried out in a reduced pressure atmosphere of orr.
引続いて冷却を行うが、還元温度からの800℃までの
冷却速度は圧縮性に影響を与えないので、コスト面より
800℃/ h r以上の冷却速度で冷却する。 この
とき、雰囲気は水素などの非酸化性雰囲気を用いると、
酸化防止の理由から好ましい。Subsequently, cooling is performed, but since the cooling rate from the reduction temperature to 800°C does not affect the compressibility, cooling is performed at a cooling rate of 800°C/hr or more from a cost standpoint. At this time, if a non-oxidizing atmosphere such as hydrogen is used,
Preferred for oxidation prevention reasons.
次に圧縮性に影響を及ぼす800℃〜300℃の冷却で
あるが、この温度範囲はCr系合金鋼粉の変態点を含み
、また結晶粒に影響を与える温度域である。 この領域
を280℃/ h r以下の冷却速度で冷却すれば製造
時間がかかり、コスト高となる。 また、600℃/
h r以上とすると、品質のバラツキの原因となり、
圧縮性の低下が起る。 そこで800〜300℃の間の
冷却速度は280〜b
する。 このとき、雰囲気として水素を用いるのは酸
化防止の理由からも好ましい。Next is cooling at 800° C. to 300° C., which affects compressibility, and this temperature range includes the transformation point of Cr-based alloy steel powder and is also a temperature range that affects crystal grains. If this region is cooled at a cooling rate of 280° C./hr or less, manufacturing time will be long and costs will be high. Also, 600℃/
If it is more than hr, it will cause variations in quality,
A decrease in compressibility occurs. Therefore, the cooling rate between 800 and 300°C is 280~b. At this time, it is preferable to use hydrogen as the atmosphere for the purpose of preventing oxidation.
300℃以下の温度範囲では冷却速度は圧縮性に影響を
与えないので、非酸化性雰囲気中で800℃/ h r
以上の冷却速度で冷却する。In the temperature range below 300 °C, the cooling rate does not affect the compressibility, so 800 °C/h r in a non-oxidizing atmosphere
Cool at the cooling rate above.
また、本発明において前述したように冷却を水素雰囲気
中で行うことは、本発明の特徴のひとつで、C10、N
の低減効果が期待できる。Furthermore, as described above, one of the features of the present invention is that cooling is performed in a hydrogen atmosphere.
can be expected to have a reduction effect.
なお水素雰囲気の圧力は爆発防止のために1.05気圧
以上とするのがよい。Note that the pressure of the hydrogen atmosphere is preferably 1.05 atm or higher to prevent explosion.
なお本発明で対象とするCr系合金鋼粉の適用例として
はCr:0.1〜5.0%に適宜Mn:0.1 〜 !
、0 % 、 Mo:0.1 〜0.5%を含むもの
を例示することができる。In addition, as an application example of the Cr-based alloy steel powder targeted in the present invention, Cr: 0.1-5.0% and Mn: 0.1-!
, 0%, and Mo: 0.1 to 0.5%.
〈実施例〉 以下に本発明を実施例に基づいて具体的に説明する。<Example> The present invention will be specifically described below based on Examples.
(実施例1)
本実施例で使用した銅粉の化学組成を表1に示す。 こ
のアトマイズ生粉を第1図に示すようにステンレス製の
8枚の受皿に充填し、それらを黒鉛製の台車に積み炉内
に搬入して還元を行った。(Example 1) Table 1 shows the chemical composition of the copper powder used in this example. As shown in FIG. 1, this atomized raw powder was filled into eight stainless steel saucers, loaded onto a graphite trolley, and carried into a furnace for reduction.
還元温度は1200℃とし、還元焼鈍された鋼粉はH2
ガスを供給した非酸化性雰囲気下で800℃まで冷却室
内に設置されているファンを回転させて冷却速度100
0℃/ h rで冷却を行った。 次に同じ水素含有雰
囲気中で20 Torr、以下まで真空ポンプによる減
圧を行い400℃までの間は230℃/ h rの冷却
速度で徐冷を行った。 次いで圧縮性に影響を及ぼさな
い400℃〜室温までは同じ<1.05気圧以上の上記
非酸化性雰囲気で再度冷却のファンを回転させて冷却速
度1000℃/ h rで冷却を行った。 以上は従来
法に基づく還元処理後の冷却方法である(第2a図参照
)。The reduction temperature was 1200℃, and the reduction annealed steel powder was heated to H2
The cooling rate was 100°C by rotating a fan installed in the cooling chamber to 800°C in a non-oxidizing atmosphere supplied with gas.
Cooling was performed at 0 °C/hr. Next, the pressure was reduced to 20 Torr or less using a vacuum pump in the same hydrogen-containing atmosphere, and gradual cooling was performed at a cooling rate of 230°C/hr until it reached 400°C. Next, cooling was performed at a cooling rate of 1000° C./hr by rotating the cooling fan again in the above non-oxidizing atmosphere at the same pressure of <1.05 atm or higher from 400° C. to room temperature, which does not affect compressibility. The above is a cooling method after reduction treatment based on a conventional method (see FIG. 2a).
次に本発明で開示した条件において同様な銅粉を用いて
第2b図に示すようにして冷却を行った。 まず還元さ
れた鋼粉をH2ガスを供給した非酸化性雰囲気下で冷却
室内に設置されているファンを回転させて、冷却速度1
000t / h rで冷却を行った。 次に1.05
気圧以上の水素雰囲気中でaOO℃〜300℃までの間
を400℃/ h rの速度で徐冷し、次いで圧縮性に
影響を及ぼさない300℃〜室温までは1.05気圧以
上の上記非酸化性雰囲気中で再度冷却のファンを回転さ
せて冷却速度1000℃/ h rで冷却を行った。Next, cooling was performed as shown in FIG. 2b using the same copper powder under the conditions disclosed in the present invention. First, the reduced steel powder is cooled at a cooling rate of 1 by rotating a fan installed in the cooling chamber in a non-oxidizing atmosphere supplied with H2 gas.
Cooling was carried out at 000 t/hr. then 1.05
It is slowly cooled at a rate of 400℃/hr from aOO℃ to 300℃ in a hydrogen atmosphere above atmospheric pressure, and then cooled at a temperature of 1.05atm or above from 300℃ to room temperature, which does not affect compressibility. The cooling fan was rotated again in an oxidizing atmosphere to perform cooling at a cooling rate of 1000° C./hr.
従来法および本発明法の冷却過程を示す第2a図および
第2b図の比較かられかるように、本発明により還元時
間が短縮できる。As can be seen from the comparison of FIGS. 2a and 2b showing the cooling process of the conventional method and the method of the present invention, the reduction time can be shortened by the present invention.
また、上述したようにして得られた従来法および本発明
による合金鋼粉について、第1図に示す各受皿の合金鋼
粉の圧粉密度を求めた。Furthermore, for the alloyed steel powders obtained by the conventional method and the present invention as described above, the green density of the alloyed steel powders in each saucer shown in FIG. 1 was determined.
従来法の結果を第3a図に、本発明法の結果を第3b図
に示す。 これらの図から本発明法によれば圧粉密度を
相当増大させることができることがわかる。The results of the conventional method are shown in FIG. 3a, and the results of the method of the present invention are shown in FIG. 3b. From these figures, it can be seen that the green powder density can be considerably increased by the method of the present invention.
なお、圧粉密度は還元した粉を解砕後、潤滑剤としてス
テアリン酸亜鉛を1%混粉後、7t/cI112の圧力
にて直径11.3mm、高さ!1〜f2mmの円柱状に
圧粉したときの圧粉体の体積(cm’)と重量(g)の
比から表される密度比である。The density of the compacted powder is determined by crushing the reduced powder, adding 1% zinc stearate as a lubricant, and applying a pressure of 7t/cI112 to a diameter of 11.3mm and height! It is a density ratio expressed from the ratio of the volume (cm') and weight (g) of a compacted powder when compacted into a cylindrical shape of 1 to f2 mm.
(実施例2)
実施例1に示した本発明法の条件中表1に示すように化
学組成を変えて800〜300℃の冷却速度を200〜
b
て、圧縮性を実施例1と同様に測定した。 得られた結
果を第4図に示す。 この図から判かるように、本発明
範囲の冷却速度において圧縮性の優れた鋼粉を得ること
ができる。(Example 2) Under the conditions of the method of the present invention shown in Example 1, the chemical composition was changed as shown in Table 1, and the cooling rate at 800 to 300°C was changed to 200 to 300°C.
b The compressibility was measured in the same manner as in Example 1. The results obtained are shown in FIG. As can be seen from this figure, steel powder with excellent compressibility can be obtained at a cooling rate within the range of the present invention.
(実施例3)
実施例1に示した本発明法の条件中表1に示すように化
学組成を変えて還元温度を700〜1350℃に変化さ
せて、圧縮性を実施例1と同様に測定した。 得られた
結果を第5図に示す。 本発明の加熱温度において、圧
縮性の優れた銅粉を得ることができた。(Example 3) Compressibility was measured in the same manner as in Example 1 by changing the chemical composition and reducing temperature from 700 to 1350°C as shown in Table 1 under the conditions of the method of the present invention shown in Example 1. did. The results obtained are shown in FIG. At the heating temperature of the present invention, copper powder with excellent compressibility could be obtained.
表 1 化学組成(重量%)
〈発明の効果〉
以上説明したように本発明法によれば、従来法で得られ
た銅粉と比較して圧粉密度が向上し、冷却時間が短くで
き、経済性が向上する。Table 1 Chemical composition (wt%) <Effects of the invention> As explained above, according to the method of the present invention, compared to copper powder obtained by the conventional method, the green powder density is improved, the cooling time can be shortened, Economic efficiency improves.
またバラツキの少ないCr系合金鋼粉を得ることができ
る。Moreover, Cr-based alloy steel powder with little variation can be obtained.
第1図は還元炉内の試料設置方法を示す線図である
第2a図および第2b図はそれぞれ従来法および本発明
法の冷却条件を比較して示す図である。
第3a図および第3b図はそれぞれ従来法および本発明
法の圧粉密度測定結果を示す図である。
第4図は冷却速度と圧粉密度の関係を示す図である。
第5図は還元温度と圧粉密度の関係を示す図FIG、1
である。
F I G、 2a
8寺
間
(hr)
F I G、 3a
受皿番号
FIG、3b
受皿番号
FI G、 2b
日づr
間(hr)
FIG、4
冷去114J!L、yt(’C/hr )FIG、5FIG. 1 is a diagram showing a method of installing a sample in a reduction furnace. FIGS. 2a and 2b are diagrams comparing cooling conditions of the conventional method and the method of the present invention, respectively. FIG. 3a and FIG. 3b are diagrams showing the results of green powder density measurement using the conventional method and the method of the present invention, respectively. FIG. 4 is a diagram showing the relationship between cooling rate and green powder density. FIG. 5 is a diagram showing the relationship between reduction temperature and green powder density. F I G, 2a 8 Terama (hr) F I G, 3a saucer number FIG, 3b saucer number FIG, 2b days r time (hr) FIG, 4 cold 114J! L,yt('C/hr)FIG,5
Claims (2)
用原料粉末を減圧雰囲気中で800℃〜1300℃の還
元温度で仕上還元焼鈍し、引き続いて冷却するに際して
、前記仕上還元温度から800℃までの間を非酸化性雰
囲気中で800℃/hr以上の速度で冷却し、その後8
00℃〜300℃までの間を水素雰囲気中で280〜6
00℃/hrの速度で冷却し、さらに300℃以下を非
酸化性雰囲気中で800℃/hr以上の速度で冷却する
ことを特徴とする合金鋼粉の仕上還元方法。(1) When the atomized raw material powder for alloy steel powder containing Cr and carbon is subjected to final reduction annealing at a reduction temperature of 800°C to 1300°C in a reduced pressure atmosphere, and subsequently cooled, from the final reduction temperature to 800°C. cooling at a rate of 800°C/hr or more in a non-oxidizing atmosphere, and then 800°C/hr or more.
00℃~300℃ in hydrogen atmosphere 280~6
A method for finishing reduction of alloy steel powder, characterized by cooling at a rate of 00°C/hr, and further cooling at a rate of 800°C/hr or more below 300°C in a non-oxidizing atmosphere.
載の合金鋼粉の仕上還元方法。(2) The method for finishing reduction of alloy steel powder according to claim 1, wherein the hydrogen atmosphere is at least 1.05 atm.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1096986A JPH0645801B2 (en) | 1989-04-17 | 1989-04-17 | Finishing heat treatment method for Cr alloy steel powder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1096986A JPH0645801B2 (en) | 1989-04-17 | 1989-04-17 | Finishing heat treatment method for Cr alloy steel powder |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH02274801A true JPH02274801A (en) | 1990-11-09 |
JPH0645801B2 JPH0645801B2 (en) | 1994-06-15 |
Family
ID=14179537
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP1096986A Expired - Lifetime JPH0645801B2 (en) | 1989-04-17 | 1989-04-17 | Finishing heat treatment method for Cr alloy steel powder |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0645801B2 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002508807A (en) * | 1997-06-17 | 2002-03-19 | ホガナス アクチボラゲット | Stainless steel powder |
US6764557B2 (en) * | 2000-01-22 | 2004-07-20 | Vulcan Strahltechnik Gmbh | Method for producing angular, stainless shot-blasting abrasives based on an fe-cr-c alloy |
JP2013204112A (en) * | 2012-03-29 | 2013-10-07 | Sumitomo Electric Sintered Alloy Ltd | Ferrous sintered alloy and method of producing the same |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61110702A (en) * | 1984-11-01 | 1986-05-29 | Kawasaki Steel Corp | Heat treatment of iron and steel powder with high productivity |
JPS61139601A (en) * | 1984-12-11 | 1986-06-26 | Toyota Motor Corp | Low-alloy iron powder for sintering and its manufacture |
JPS62107001A (en) * | 1985-11-05 | 1987-05-18 | Kawasaki Steel Corp | Finish heat treatment method for reduced iron powder |
-
1989
- 1989-04-17 JP JP1096986A patent/JPH0645801B2/en not_active Expired - Lifetime
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61110702A (en) * | 1984-11-01 | 1986-05-29 | Kawasaki Steel Corp | Heat treatment of iron and steel powder with high productivity |
JPS61139601A (en) * | 1984-12-11 | 1986-06-26 | Toyota Motor Corp | Low-alloy iron powder for sintering and its manufacture |
JPS62107001A (en) * | 1985-11-05 | 1987-05-18 | Kawasaki Steel Corp | Finish heat treatment method for reduced iron powder |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2002508807A (en) * | 1997-06-17 | 2002-03-19 | ホガナス アクチボラゲット | Stainless steel powder |
JP2010196171A (en) * | 1997-06-17 | 2010-09-09 | Hoganas Ab | Stainless steel powder |
US6764557B2 (en) * | 2000-01-22 | 2004-07-20 | Vulcan Strahltechnik Gmbh | Method for producing angular, stainless shot-blasting abrasives based on an fe-cr-c alloy |
JP2013204112A (en) * | 2012-03-29 | 2013-10-07 | Sumitomo Electric Sintered Alloy Ltd | Ferrous sintered alloy and method of producing the same |
Also Published As
Publication number | Publication date |
---|---|
JPH0645801B2 (en) | 1994-06-15 |
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