Journal of Shanghai University(Natural Science Edition) ›› 2015, Vol. 21 ›› Issue (5): 663-670.doi: 10.3969/j.issn.1007-2861.2014.01.033

• Metallurgical Materials • Previous Articles    

Transformation and retained austenite of two kinds of bainite plastic mold steel

LI Na, MIN Yong-an, ZHANG Zheng, WU Xiao-chun   

  1. School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China
  • Received:2014-01-16 Online:2015-10-30 Published:2015-10-30

Abstract: FT600 and FT600mod steels are two similar non-quenched plastic mold steels with difference in the content of Si and Mn. Both FT600 and FT600mod were cooled by
continuous and isothermal treatments after austenitizing respectively, and then separately tempered at 350, 580, and 700 °C. Evolution of microstructures and retained austenite of the two bainitic steels after the heat treatments are studied based on the microstructure characterization, content measurement, and Rockwell hardness and dilatometric analysis experiments. It is found that the content of the retained austenite of continuous cooling sample of FT600mod, different from FT600 by decreasing Si and increasing Mn, is decreasing dramatically. The changed amounts of retained austenite of FT600 sample vary after different tempering treatments. FT600mod steels are more stable and more suitable for the non-quenched treatment.

Key words: bainite, cooling transformation, retained austenite decomposition/transformation, tempering

CLC Number: