Effect of Sintering Atmosphere and Carbon Addition on Sintered Density of M3/2 Grade High Speed Steel Powder

M3/2계 고속도 공구강 분말의 소결분위기와 탄소첨가가 소결밀도에 미치는 영향

  • Ahn, Jin-Hwan (Dept. of Metallurgical Engineering, Dong-A University) ;
  • Heo, Jong-Seo (Dept. of Metallurgical Engineering, Dong-A University) ;
  • Joo, Dong-Won (Dept. of Metallurgical Engineering, Dong-A University) ;
  • Jung, Eun (School of Materials and Metallurgical Engineering, Ulsan University) ;
  • Sung, Jang-Hyun (Dept. of Metallurgical Engineering, Dong-A University)
  • 안진환 (동아대학교 금속공학과) ;
  • 허종서 (동아대학교 금속공학과) ;
  • 주동원 (동아대학교 금속공학과) ;
  • 정은 (울산대학교 재료금속공학부) ;
  • 성장현 (동아대학교 금속공학과)
  • Published : 1998.12.01

Abstract

For the purpose of investigating the effect of sintering atmosphere and carbon addition on sintered density and microstructural characteristics, the M3/2 grade high speed steel powders with the addition of carbon are sintered in vacuum and $20%H_2/79%N_2/l%CH_4$ gas atmosphere. With the addition of 0 wt%C, 0.45wt%C and 1.15 wt%C the optimum sintering temperatures decrease down to $1260^{\circ}C$, $1210^{\circ}C$ and $1150^{\circ}C$ respectively for the vacuum sintered specimen, and also decrease down to $1130^{\circ}C$, $1120^{\circ}C$ and $1115^{\circ}C$ for the gas sintered specimen. The threshold temperatures for full densification decrease steeply with increasing carbon content of the sintered specimen, while this temperatures are slowly decreased at high carbon content. The vacuum sintered specimen shows the primary carbides of MC and $M_6C$ type at the optimum sintering temperature, and eutectic carbides of $M_2C$ and Fe-Cr type are produced in the oversintered specimen. The gas sintered specimen exhibits M6C and Fe-Cr type primary carbides at the optimum sintering temperature. The eutectic carbides of $M_6C$ and Fe-Cr type and MX type carbonitride are shown for the oversintered specimen in the gas atmosphere. The hardness of gas sintered specimen shows high value of 830-860 Hv due to the increment of carbide precipitation.

Keywords

References

  1. Powder Metallurgy v.2 F.D.Kirk
  2. 대한금속학회회보 v.6 no.2 정형식;김병기;김용진
  3. ASM(Ninth Ed.) v.7 Metals Handbook D.J.Blickwede
  4. 特殊鋼 v.32 鈴木;淸石
  5. MPLE; v.1 Powder Injection Molding R.M.German
  6. MPR DEC A.Aguirre;S.Talacchia;J.J.Urcola
  7. Int J.of P/M v.26 no.1 R.M.German
  8. Int.J.of P/M v.26 no.1 R.M.German
  9. Powder Metallurgy v.32 no.2 C.S.Wright
  10. Powder Metallurgy v.36 no.3 C.S.Wright;B.Ogel.
  11. Int J.of P/M v.29 no.2 P.K.Kar;B.P.Saha;G.S.Upadhyaya
  12. 대한금속학회 제 3회 분말야금심포지엄 정형식;김용진
  13. 한국분말야금학회지 v.4 이광희;주동원;구광덕;심재진;성장현
  14. High speed steel G.Hoyle
  15. Bull.Ameri.Ceramic.Soci. v.57 no.2 P.K.Willenmet;R.A.pett;T.J.whalen
  16. Powder Metallurgy v.33 no.4 Urrutibeaska,R.Plma;V.Martinez;J.J.Urcola
  17. Powder Metallurgy v.32 no.4 R.H.Palma;V.Martinez;J.J.Urcola