오스템퍼링 처리가 열간압연롤용 NICI재 및 DCI재의 미세조직 및 기계적 성질에 미치는 영향

The Effect of Austempering Treatment on Microstructure and Mechanical Properties of NICI and DCI for Rolls Used in Hot Rolling Mill

  • 발행 : 2009.12.31

초록

The effect of austempering treatment on mechanical properties of nodular indefinite chilled iron(NICI) and ductile cast iron(DCI) was investigated. In microstructural observation, matrix phase(pearlite and ferrite) was changed to ausferrite after austempering treatment both DCI and NICI. In case of NICI, decomposition of cementite($Fe_3C$) during austempering treatment was induced. After austempering treatment, mechanical properties such as hardness, tensile strength and impact toughness was improved in NICI and DCI. The wear resistance is slightly decreased because of decomposition of cementite during austempering treatment in NICI but impact toughness and strength is dramatically increased.

키워드

참고문헌

  1. S. Spuzic, K.N. Strafford, C. Subramanian and G. Savage: Wear, "Wear of hot rolling mill rolls: an overview, Wear". 176, (1994) 261-271 https://doi.org/10.1016/0043-1648(94)90155-4
  2. S. E. Lundberg and T. Gustafsson: J. Mat. Process. Technol., "The Influence of Rolling Temperature on Roll Wear, "Investigated in a New High Temperature Test Rig". 42, (1994) 239-291 https://doi.org/10.1016/0924-0136(94)90181-3
  3. S. E. Lundberg: Steel Research, "Evaluation of deterioration mechanisms and roll life different roll materials", 64, (1993) 597-603 https://doi.org/10.1002/srin.199301577
  4. M. Shimizu, O. Shitamura, S. Matsuo, T. Kamata, and Y. Kondo: ISIJ Int., "Development of High Performance New Composite Roll", 32, issue: 11, (1992) 1244-1249 https://doi.org/10.2355/isijinternational.32.1244
  5. D. Suh, S. Lee, Y. Koo and H. C. Lee, Metallurgical and Materials Transactions A, 27A, (1996) 3149
  6. ASM Specialty Handbook, Cast Irons(eds., J. R. Davis), ASM international, Material Park (1996) 192
  7. A. S. Hamid Ali and R. Elliott: Materials Science and Technology, "Influence of Austenitizing Temperature on Austempering of an Mn-Mo-Cu Alloyed Ductile Iron. I. Austempering Kinetics and the Processing Window", 12, 12 (1996) 1021-1031 https://doi.org/10.1179/026708396790121982
  8. A. S. Hamid Ali and R. Elliott: Materials Science and Technology, "Influence of Austenitising Temperature on Austempering of an Mn-Mo-Cu Alloyed Ductile Iron. II. Mechanical Properties" 13, (1997) 24-30 https://doi.org/10.1179/026708397790242888
  9. J. Mallia, M. Grech, and R. E. Smallman: Materials Science and Technology, "Effect of Silicon Content on Transformation Kinetics of Austempered Ductile Iron" 14, 5, (1998) 452-460 https://doi.org/10.1179/026708398790301223
  10. N. Darwish and R. Elliot: Materials Science and Technology, "Austempering of low manganese ductile irons, Part 1: Processing window" 9, (1993) 572-585 https://doi.org/10.1179/026708393790172286
  11. N. Darwish and R. Elliot: Materials Science and Technology, Austempering of low manganese ductile irons, Part II: Influence of austenitising temperature" 9, (1993) 586-602 https://doi.org/10.1179/026708393790172268
  12. N. Darwish and R. Elliot: Materials Science and Technology, "Austempering of low manganese ductile irons Part 3 Variation of mechanical properties with heat treatment conditions" 9, (1993) 882-889 https://doi.org/10.1179/026708393790171449
  13. A. S. Hamid Ali, K. I. Uzlov, N. Darwish and R. Elliot: Materials Science and Technology, "Austempering of Low Manganese Ductile Irons Part 4: Relationship Between Mechanical Properties and Microstructure" 10, (1994) 35-40 https://doi.org/10.1179/026708394790163429
  14. H. Bayati and Elliot: Materials Science and Technology, "Austempering Process in High Manganese Alloyed Ductile Cast Iron", 11, 2, (1995) 118-129 https://doi.org/10.1179/026708395790164751
  15. N. K. Datta and N. N. Engel: AFS Transaction, 74, (1985) 267
  16. A. D. Sarkar: Int. Series in Materials Science and Technology, 18, Pergamon Press, (1976) 71