JPS6157362B2 - - Google Patents
Info
- Publication number
- JPS6157362B2 JPS6157362B2 JP53112981A JP11298178A JPS6157362B2 JP S6157362 B2 JPS6157362 B2 JP S6157362B2 JP 53112981 A JP53112981 A JP 53112981A JP 11298178 A JP11298178 A JP 11298178A JP S6157362 B2 JPS6157362 B2 JP S6157362B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- density
- hot
- hot forging
- high density
- 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
- 239000000843 powder Substances 0.000 claims description 39
- 238000000034 method Methods 0.000 claims description 28
- 238000005242 forging Methods 0.000 claims description 23
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 238000010791 quenching Methods 0.000 claims description 12
- 230000000171 quenching effect Effects 0.000 claims description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- 230000006698 induction Effects 0.000 claims description 3
- 238000005121 nitriding Methods 0.000 claims description 2
- 238000003303 reheating Methods 0.000 claims description 2
- 230000006835 compression Effects 0.000 claims 1
- 238000007906 compression Methods 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 description 12
- 238000005496 tempering Methods 0.000 description 7
- 238000007796 conventional method Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000005275 alloying Methods 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000005256 carbonitriding Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
本発明は真密度の95％以上の密度を有する高密
度粉末成形品を粉末熱間鍛造法により製造する方
法に関する。
粉末熱間鍛造法により、鉄系の高密度粉末成形
品を得る方法は従来第１図に示すような方法によ
り実施され、一部実用に供せられている。
しかし、工程が長い為、材料歩留りの向上、高
寸法精度、高生産性といつた利点があるにもかか
わらず製造コストが高くなり、溶製材の切削加工
法、冷間鍛造法などの競合プロセスと比較して、
経済的な製造法として一般に普及するまでには致
つていない。
本発明は、このような実態を改善する為になさ
れたもので、性能を損うことなく工程を簡略化す
ることにより、安価でかつ高品位な製品の製造法
を提供するものである。従来第１図に示すような
方法において、焼結工程と加熱工程を連続化させ
る方法が改善策として考えられたが、設備的に過
大なものとなり、予備成形体の酸化、脱炭あるい
は浸炭等が生じやすくなるなど品質上においても
好ましくなかつた。
又、第１図における焼結工程を省略し、予備成
形体を直接加熱して熱間鍛造を行なう方法も案出
された。しかし、この方法においては、炭素を含
め数種の材質成分を純成分に近い粉末で添加混合
して目的組成を生成する為、拡散合金化の為の加
熱時間が必要であるにもかかわらず、一般には加
熱時間が短かい為に十分合金化されず、熱間鍛造
後に再拡散工程を必要とし品質上及び経済上好ま
しくなかつた。
本発明による方法は、原料粉末として完全合金
化した金属粉末を使用することにより、加熱時間
を必要最小限にとどめるだけでよい為に製造工程
全体が短縮され、低コストで高品質の粉末成形品
を製造することが出来るものである。
すなわち、炭素を含め、合金元素を完全合金化
した粉末をプレス等により予備圧縮成形した後、
保護雰囲気中においてオーステナイト化温度以上
に加熱する。加熱された予備成形体にプレス等に
より熱間鍛造を施して、真密度の95％以上の密度
を有するように圧密化する。このようにして得ら
れた高密度粉末成形体は十分な強度を有してお
り、鍛造した直後に急冷焼入処理を行ない、焼戻
処理するか、あるいは焼入後窒化、高周波焼入等
の熱処理を行うか、あるいは再加熱して焼入焼戻
しを行なうだけで十分な機械的性能が得られるこ
とが明らかになつた。
本発明中における予備加熱の条件は、オーステ
ナイト化温度以上に加熱するだけでよいが、直ち
に焼入れ処理を行う為には鍛造直後において鍛造
体の温度が焼入温度以上であるように設定するこ
とが望ましい。
炭素は予備加熱中に原料粉末中の酸素と反応し
て含有酸素量を低減させ、又酸化を防止し良好な
鍛造体を得る為に不可欠である。
つまり熱間鍛造前の加熱段階に於て粉末表面が
清浄に保たれる為熱間鍛造だけで強固な界面結合
が達成される。
勿論、一般に鋼の強度特性を向上させる為には
0.2〜0.8％の炭素を含有することが必要である
が、本発明による方法においては、炭素と反応し
て消失する為に0.4〜1.0％の炭素を予め含有して
おくことが必要である。
以下実施例により詳細に説明する。
実施例 １
第１表に示す組成の粉末をプレスにより６ton/
cm2の加圧力で予備成形し10×10×55mmの形状で密
度6.2ｇ/cm3の圧粉成形体を得た。
この予備成形体をN2雰囲気中で1200℃−10min
加熱した後、加熱炉より取り出し、約5sec以内に
金型中で10ton/cm3鍛造圧力で熱間鍛造を行なつて
7.8ｇ/cm3の密度まで圧密化し、直ちに油温20℃の
焼入油中に投入して急冷焼入し、10×10×55mmの
高密度粉末成形体を得た。
この後、N2雰囲気中で600℃−60min焼戻処理
を行なつて強度特性を測定した。
又、第１図に示す従来法により1130℃−20min
及熱性変成ガス雰囲気中で焼結した後、同一条件
で予備加熱、熱間鍛造を行ない、同様の焼戻処理
を行なつて得られた高密度粉末成形品の特性を本
発明法により得られた特性と比較して第２表に示
す。
本発明法により得られた高密度粉末成形品の方
が高い強度特性を示しており、かつ工程が短縮さ
れている為に経済的な製造法となつており、本発
明の効果が明らかである。
The present invention relates to a method for manufacturing a high-density powder molded product having a density of 95% or more of the true density by a powder hot forging method. A method of obtaining a high-density iron-based powder molded product by a powder hot forging method has been conventionally carried out as shown in FIG. 1, and some of the methods have been put to practical use. However, because the process is long, manufacturing costs are high despite the advantages of improved material yield, high dimensional accuracy, and high productivity. compared to
It has not yet become widespread as an economical manufacturing method. The present invention has been made to improve this situation, and provides a method for manufacturing inexpensive and high-quality products by simplifying the process without impairing performance. Conventionally, a method to improve the method shown in Figure 1 was to serialize the sintering process and the heating process, but this would require too much equipment and would cause problems such as oxidation, decarburization, or carburization of the preform. It is also unfavorable in terms of quality, as it tends to cause problems. A method has also been devised in which the sintering step in FIG. 1 is omitted and the preform is directly heated for hot forging. However, in this method, several material components including carbon are added and mixed as powder close to pure components to create the desired composition, so even though heating time is required for diffusion alloying, In general, because the heating time is short, the alloy is not sufficiently alloyed, and a re-diffusion step is required after hot forging, which is unfavorable in terms of quality and economy. By using fully alloyed metal powder as the raw material powder, the method of the present invention shortens the entire manufacturing process because only the heating time is kept to the minimum necessary, resulting in low-cost, high-quality powder molded products. can be manufactured. That is, after pre-compression molding a powder in which alloying elements including carbon are completely alloyed using a press or the like,
Heating above the austenitizing temperature in a protective atmosphere. The heated preform is subjected to hot forging using a press or the like, and is consolidated to have a density of 95% or more of the true density. The high-density powder compact obtained in this way has sufficient strength, and can be rapidly quenched and tempered immediately after forging, or subjected to nitriding, induction hardening, etc. after quenching. It has become clear that sufficient mechanical performance can be obtained simply by heat treatment or by reheating and quenching and tempering. The preheating conditions in the present invention are simply heating to a temperature higher than the austenitizing temperature, but in order to perform the quenching process immediately, it is necessary to set the temperature of the forged body to be higher than the quenching temperature immediately after forging. desirable. Carbon reacts with oxygen in the raw material powder during preheating to reduce the amount of oxygen contained, and is essential for preventing oxidation and obtaining a good forged body. In other words, since the powder surface is kept clean during the heating stage before hot forging, a strong interfacial bond can be achieved only by hot forging. Of course, in general, in order to improve the strength properties of steel,
Although it is necessary to contain 0.2 to 0.8% carbon, in the method according to the present invention, it is necessary to previously contain 0.4 to 1.0% carbon in order to react with carbon and disappear. This will be explained in detail below using examples. Example 1 6 tons/powder with the composition shown in Table 1 was pressed.
It was preformed under a pressure of cm 2 to obtain a powder compact with a shape of 10×10×55 mm and a density of 6.2 g/cm 3 . This preform was heated at 1200℃ for 10min in an N2 atmosphere.
After heating, take it out of the heating furnace and hot forge it in the mold at a forging pressure of 10ton/ cm3 within about 5 seconds.
It was compacted to a density of 7.8 g/cm 3 and immediately put into quenching oil at a temperature of 20° C. for rapid cooling and quenching to obtain a high-density powder compact of 10×10×55 mm. Thereafter, a tempering treatment was performed at 600° C. for 60 minutes in a N 2 atmosphere, and the strength characteristics were measured. Also, by the conventional method shown in Figure 1, 1130℃-20min
After sintering in an exothermic modified gas atmosphere, preheating and hot forging were performed under the same conditions, and the characteristics of a high-density powder molded product obtained by performing a similar tempering treatment were obtained by the method of the present invention. Table 2 shows a comparison of the characteristics. The high-density powder molded product obtained by the method of the present invention exhibits higher strength characteristics, and the process is shortened, making it an economical manufacturing method, which clearly demonstrates the effects of the present invention. .
【表】
実施例 ２
実施例１において熱間鍛造により圧密化し、直
ちに急冷焼入処理した後、570℃−120min窒化処
理を行なつた。
得られた高密度粉末成形品の特性を第２表に示
す。従来法に比較して強度特性、耐摩耗性、耐食
性に優れた高密度粉末成形品が得られた。
実施例 ３
実施例１において熱間鍛造により圧密化し、直
ちに急冷処理した後、高周波焼入処理を行ない、
焼戻処理を行なつて強度特性を測定した。
得られた特性を第２表に示す。
従来法に比較して強度特性、耐摩耗性に優れた
高密度粉末成形品を得ることが出来た。[Table] Example 2 In Example 1, the material was compacted by hot forging, immediately quenched and then nitrided at 570°C for 120 minutes. Table 2 shows the properties of the obtained high-density powder molded product. A high-density powder molded product with superior strength properties, wear resistance, and corrosion resistance compared to conventional methods was obtained. Example 3 In Example 1, the material was compacted by hot forging, immediately quenched, and then induction hardened.
A tempering treatment was performed and the strength properties were measured. The properties obtained are shown in Table 2. We were able to obtain a high-density powder molded product with superior strength properties and wear resistance compared to conventional methods.
【表】
実施例 ４
実施例１において熱間鍛造により得られた高密
度粉末成形体を室温まで冷却した後、870℃−
120min加熱し焼入処理を行ない、その後600℃−
60min焼戻処理を行なつて強度特性を測定した。
得られた特性を従来法により焼入・焼戻処理を
行なつたものと比較して第３表に示す。本発明に
よる効果が明らかである。[Table] Example 4 After cooling the high-density powder compact obtained by hot forging in Example 1 to room temperature,
Heat for 120min for quenching treatment, then 600℃-
The strength properties were measured after tempering for 60 minutes. Table 3 shows the properties obtained in comparison with those obtained by quenching and tempering using conventional methods. The effects of the present invention are obvious.
第１図は従来の粉末熱間鍛造法による高密度粉
末成形体の製造方法を、第２図は本発明における
粉末熱間鍛造法による高密度粉末成形体の製造法
を夫々模式図により示したものである。図中１，
１′は原料粉で、１′は鉄粉に炭素粉及び潤滑剤等
を加えたもの、１は鋼粉に潤滑剤等を加えたも
の、２，２′は混合、３，３′は予備成形、４′は
1000〜1250℃ 20〜30minの焼結、５′は加熱、
６′は熱間鍛造で900〜1100℃ １〜15minで行な
われ、５は加熱、６は熱間鍛造＋急冷焼入で、
1000〜1250℃ 10〜30minで行なわれ、７は870
〜920℃ 30〜180minによる浸炭窒化焼入、８，
８′は180〜700℃ 60〜90minによる焼戻しを示
す。
Fig. 1 schematically shows a method for manufacturing a high-density powder compact using the conventional powder hot forging method, and Fig. 2 schematically shows a method for producing a high-density powder compact using the powder hot forging method according to the present invention. It is something. 1 in the figure,
1' is raw material powder, 1' is iron powder with carbon powder and lubricant, etc., 1 is steel powder with lubricant, etc., 2 and 2' are mixed, and 3 and 3' are preliminary. Molding, 4'
Sintering at 1000-1250℃ for 20-30min, heating at 5',
6' is hot forging at 900-1100℃ for 1-15 minutes, 5 is heating, 6 is hot forging + rapid quenching,
1000-1250℃ 10-30min, 7 is 870
Carbonitriding and quenching at ~920℃ for 30~180min, 8.
8' indicates tempering at 180-700°C for 60-90 min.
Claims (1)
で0.4〜1.0％含み予め合金化した粉末をプレス等
により予備圧縮成形した後、オーステナイト化温
度以上に加熱し、熱間で再圧縮して95％以上の高
密度とした後、熱処理を行なうことを特徴とする
粉末熱間鍛造法による高密度粉末成形品の製造方
法。 ２ 熱間で再圧縮して95％以上の高密度とした
後、直ちに急冷して焼入焼戻し処理を行なうこと
を特徴とする特許請求の範囲第１項記載の粉末熱
間鍛造法による高密度粉末成形品の製造方法。 ３ 熱間で再圧縮して95％以上の高密度とし、直
ちに急冷した後、窒化処理を施すことを特徴とす
る特許請求の範囲第２項記載の粉末熱間鍛造法に
よる高密度粉末成形品の製造方法。 ４ 熱間で再圧縮して95％以上の高密度とし、直
ちに急冷した後、高周波焼入処理を施すことを特
徴とする特許請求の範囲第２項記載の粉末熱間鍛
造法による高密度粉末成形品の製造方法。 ５ 熱間で再圧縮して95％以上の高密度とした
後、再加熱を行なつて焼入温度以上の温度にした
後、焼入処理を行なうことを特徴とする特許請求
の範囲第１項記載の粉末熱間鍛造法による高密度
粉末成形品の製造方法。[Claims] 1 A pre-alloyed powder containing Fe as the main component and at least 0.4 to 1.0% by weight of carbon is pre-compression molded using a press or the like, heated to a temperature equal to or higher than the austenitizing temperature, and heated to a hot temperature. A method for producing a high-density powder molded product using a powder hot forging method, which is characterized by recompressing the product to a high density of 95% or more and then heat-treating the product. 2. High density produced by the powder hot forging method according to claim 1, characterized in that the powder is hot recompressed to a high density of 95% or more, and then immediately quenched and quenched and tempered. Method for manufacturing powder molded products. 3. A high-density powder molded product by the powder hot forging method according to claim 2, which is hot recompressed to a high density of 95% or more, immediately quenched, and then subjected to nitriding treatment. manufacturing method. 4. High-density powder obtained by the powder hot forging method according to claim 2, which is hot recompressed to a high density of 95% or more, immediately quenched, and then subjected to induction hardening treatment. Method of manufacturing molded products. 5. Claim 1, characterized in that after hot recompression to a high density of 95% or more, reheating is performed to a temperature equal to or higher than the quenching temperature, and then a quenching treatment is performed. A method for producing a high-density powder molded product by the powder hot forging method described in 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11298178A JPS5538983A (en) | 1978-09-13 | 1978-09-13 | Production of high density powder molding by powder hot forging process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11298178A JPS5538983A (en) | 1978-09-13 | 1978-09-13 | Production of high density powder molding by powder hot forging process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5538983A JPS5538983A (en) | 1980-03-18 |
| JPS6157362B2 true JPS6157362B2 (en) | 1986-12-06 |
Family
ID=14600405
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11298178A Granted JPS5538983A (en) | 1978-09-13 | 1978-09-13 | Production of high density powder molding by powder hot forging process |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5538983A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60145370A (en) * | 1984-01-07 | 1985-07-31 | Sumitomo Electric Ind Ltd | Manufacture of sintered soft magnetic parts having superior corrosion resistance |
| JPH0680164B2 (en) * | 1984-11-09 | 1994-10-12 | トヨタ自動車株式会社 | Sintered forged product manufacturing method |
| JPH0499129A (en) * | 1990-08-07 | 1992-03-31 | Mitsubishi Materials Corp | Heat treatment of annular material |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4986205A (en) * | 1972-09-05 | 1974-08-19 | ||
| JPS5281004A (en) * | 1975-12-29 | 1977-07-07 | Kobe Steel Ltd | Heating of formed body by powder forging and powder aggregate using ca rbon steel powder |
| JPS5326207A (en) * | 1976-08-23 | 1978-03-10 | Federal Mogul Corp | Process for production of casting product of powdered metal |
| JPS5367608A (en) * | 1976-11-29 | 1978-06-16 | Honda Motor Co Ltd | Carburizing * forging and quenching of ferrous powder molded article |
-
1978
- 1978-09-13 JP JP11298178A patent/JPS5538983A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4986205A (en) * | 1972-09-05 | 1974-08-19 | ||
| JPS5281004A (en) * | 1975-12-29 | 1977-07-07 | Kobe Steel Ltd | Heating of formed body by powder forging and powder aggregate using ca rbon steel powder |
| JPS5326207A (en) * | 1976-08-23 | 1978-03-10 | Federal Mogul Corp | Process for production of casting product of powdered metal |
| JPS5367608A (en) * | 1976-11-29 | 1978-06-16 | Honda Motor Co Ltd | Carburizing * forging and quenching of ferrous powder molded article |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5538983A (en) | 1980-03-18 |
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