Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
권호 표지

Variation of Microstructure and Property of the Electro-slag Remelted M2 Steel with Heat Treatment Conditions

ESR한 M2강의 열처리에 따른 미세조직 및 물성 변화

  • Lee, Ki-Jong (Department of Metallurgical and Material and Materials Engineering, Inha Technical College) ;
  • Kim, Moon-Hyun (School of Materials Science and Engineering, Inha University) ;
  • Lee, Jeong-Keun (School of Materials Science and Engineering, Inha University) ;
  • Joo, Dae-Heon (School of Materials Science and Engineering, Inha University) ;
  • Kim, Myung-Ho (School of Materials Science and Engineering, Inha University)
  • 이기종 (인하공업전문대학 금속재료과) ;
  • 김문현 (인하대학교 재료공학부) ;
  • 이정근 (인하대학교 재료공학부) ;
  • 주대헌 (인하대학교 재료공학부) ;
  • 김명호 (인하대학교 재료공학부)
  • Published : 2002.12.20
Download PDF
⟨ Previous Next ⟩

Abstract

In order to investigate the variation of microstructure and property of the Electro-slag Remelted M2 steel, microstructure observation, hardness, and bending test were performed by using optical microscope. SEM/EDS, rockwell hardness tester, charpy impact tester and bending tester, respectively. It was revealed that the number of inclusions and content of gas elements(S, O, N) in M2 steel fabricated by ESR process decreased markedly compared to those of AIM. It seems to be due to refining effect of ESR process. The volume fraction of carbides in quenched and tempered specimens after austenitizing at 1150$^{\circ}C$ and 1240$^{\circ}C$ was measured. The volume fraction of grain boundary carbides were found to be similar for both specimens. However, The volume fraction of carbides in grain decreased with an increase of austenitizing temperature. When specimen was austenitized at 1150$^{\circ}C$, grain boundary carbides showed needle like morphology. But, the carbides were broken with an increase of austenitizing temperature. The specimen austenitized at 1240$^{\circ}C$ showed higher hardness and lower bending strength compared to that of 1150$^{\circ}C$. As expected, toughness increased with sub-zero quenching treatment.

Keywords

References

  1. S. W. Kim, U. J. Lee, K. D. Woo and D. K. Kim : J. Kor. Foundrymen's Soc., 'Influence of Vertical Centrifugal Casting (V. C. C) Conditions and Alloying Elements of Microstructures of High Speed Steel' 20 (2000) 323-329
  2. G. Roberts and R.Cary: TOOL STEEL
  3. T. K. Kim, S. T. Park and S. S. Kim : J. Kor. Inst. Met. & Mater., 'Research on the Machinability and Corrosion Resistance of Fe-Cr-Ni Alloy' 35 (1997) 697-703
  4. R. J. Hawkins, D. J. Swinden and D. N. Pocklington : Proceedings of a conference on Electroslag refining. 'RELE-VANCE OF LABORATORY EXPERIMENTS TO THE CONTROL OF COMPOSITION IN PRODUCTION-SCALE ESR' (1974) 21-34
  5. J. Choi, M. C. Shin, M. Mun, C. R. Kim, S. H. lee and H. S. Choi: J. Kor. Inst. Met. & Mater., 'On the Remelting of spe-cialty Steels by the electroslag Remelting Process: 14 (1976) 31-39
  6. E. J. Galda and R. W. Kraft: Met. Trans., 'The Effects of Mo and W on Solidification of High Speed Steels' 5 (1974) 1727-1733 https://doi.org/10.1007/BF02644134
  7. K. Stiller, L-E. Svensson, P. R. Howell, Wang Rong, H-G. Andren and G. L. Dunlop: Acta metall., 'HIGH RESOLU-TION MICROANALYTICAL STUDY OF PRECIPITA-TION IN POWDER METALLURGICAL HIGH SPEED STEEL' 32, No. 9 (1984) 1457-1467 https://doi.org/10.1016/0001-6160(84)90092-0
  8. Wlliam C. Leslie : The physical metallurgy of steels. 216-218
  9. S. C. Lee and F. J. Worzala : Met. Trans., $^{\circ}X$ Fracture Behavior of AISI M-2 High Speed Tool Steel" 12A (1981) 1477-1484