Temperature and Strain-Rate Effect to Mechanical Behavior of Mo-Cr Alloy Cast Iron

Abstract:

Mo-Cr alloy cast iron is the most important material often used to make auto panel dies. To study high-speed machining process of auto panel dies, the material’s elastic modulus and fracture critical values of Mo-Cr alloy iron at 20°C-800°C were studied based on the high temperature elongation test. The material’s stress-strain relation curves at various temperatures (20°C-500°C) and various strain-rates (500/s-5000/s) were studied and the dynamic tensile yield strength values were obtained by dynamic SHPB(Split Hopkinson Pressure Bar) high-speed compression test. The test observation showed that Mo-Cr alloy iron has heat resistance and its behavior is between toughness and brittleness materials. Its toughness is enhanced with temperature increasing. At 20°C-500°C and strain-rates (500/s-5000/s) the dynamic tensile yield strength is decreased about 17％-24％ by temperature softening effect and is increased about 56％-70％ by strain-rate strengthening effect. The strain-rate strengthening effect prevails over temperature softening effect. Keywords: Auto panel die; Mo-Cr alloy cast iron; SHPB; Temperature softening effect; Strain-rate strengthening effect

• Periodical: Materials Science Forum (Volumes 704-705)
• Pages: 918-922
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.704-705.918
• Online since: December 2011
• Authors: Jing Kui Ruan, Ming Mao Hu
• Keywords: Auto Panel Die, Mo-Cr Alloy Cast Iron, SHPB, Strain-Rate Strengthening Effect, Temperature Softening Effect

References

[1] Dj.M. Maric, P.F. Meier and S.K. Estreicher: Mater. Sci. Forum Vol. 83-87 (1992), p.119.

[1] ZI Shu. Metallurgical basis of Hi-Cr white irons. Modern Cast Iron, 2007, (7): pp.29-32.

[2] QIAN Quansen. The research of producing draw cite using nodular iron. Research Studies on Foundry Eqipment., 1997 (5): 25-26.

[3] ZHOU Yong xin; LU Zhen lin. Research on microstructure and properties of the bainite white Iron grinding ball as-cast. Hot Working Technology, 2001, (2): pp.31-34.

[4] CHEN Meiling, LI Jianwei, GAO Hong. Research on the microstructure and mechanical properties of surface modified SiC nanometer powders reinforced nodular cast iron , Materials Review, 2006(F05): pp.214-215.

[5] GONG Wenbang; CHEN Liliang; LIU Ruixiang, etc. Production technics and mechanical properties of high toughness austempered ductile iron. Materials for Mechanical Engineering, 2007, 31(8): pp.51-53.

[6] S. P. F. C. Jaspers, J. H. Dautzenberg. Material behaviour in metal cutting: strains, strain rates and temperatures in chip formation. Journal of Materials Processing Technology, 2002, 121: pp.123-135.

DOI: 10.1016/s0924-0136(01)01227-4

[7] P. Fallbohmer, C.A. Rodriguez. T. Ozel and T. Altan: High-speed machining of cast iron and alloy steels for die and mold manufacturing, Journal of Materials Processing Technology 98 (2000): pp.104-115.

DOI: 10.1016/s0924-0136(99)00311-8

[8] J. Shuda, Z. Dongsheng. in: Mechanics of Materials. China Metallurgical Industry Press, Beijing, (1996).

[9] H. Changming, H. Hongliang and H. Shisheng. A study on dynamic mechancial behaviors of 45 steel. Explosion and Shock Waves, 2003, 23(2): pp.188-192.

[10] L. Hollang, D. Brunner and A. Seeger. Work hardening and flow stress of ultrapure molybdenum single crystals[J]. Materials Science and Engineering. 2001, A319-321: pp.233-236.

DOI: 10.1016/s0921-5093(01)01002-4