Hong-Yan Wu
Northeastern University, China
Title: Effect of tempering time on strength and toughness of a ultra-low C medium Mn steel
Biography
Biography: Hong-Yan Wu
Abstract
A ultra-low C medium Mn steel was subjected to controlled rolling and water quenching, and then the steel plate was intercritically tempered at 650ºC for 30min and 50min, respectively. The microstructure consisted of duplex laminate structure of tempered martensite and reversed transformed austenite. The high yield strength of 780MPa and good low temperature toughness of 135J at -60ºC were obtained when the quenched steel was tempered for 30min. As the tempering time increasing to 50min, the yield strength was decreased to 685MPa, while the tensile strength of 860MPa was unchanged, leading to reduced yield ratio. Moreover, the impact energy at -60ºC was slightly enhanced to 150J. The variation of mechanical properties was influenced by the stability of austenite.