Effect of partitioning of quenchingpartitioningtempering process on microstructures and hardness.pdf

Advanced Materials Research Vols. 538-541 (2012) pp 1053-1056 Online available since 2012/Jun/14 at © (2012) Trans Tech Publications, Switzerland doi:10.4028//AMR.538-541.1053 Effect of partitioning of quenching-partitioning-tempering process on microstructures and hardness in high carbon steels a b c d Yangzheng Zeng , Kaiming Wu , Feng Hu and Hua Zheng International Research Institute for Steel Technology, Wuhan University of Science and Technology, Wuhan 430081, China a b c zyangz1986@163.com, wukaiming@, hufenghf@126.com, dzhenghua1198@163.com Keywords: High carbon steel, Q-P-T process, Partitioning, Microstructure, Hardness Abstract: The effect of partitioning process of quenching-partitioning-tempering (Q-P-T) process on hardness and microstructure were investigated. The 1-step Q-P-T and 2-step Q-P-T heat treatment were designed and carried out. The microstructure and carbides were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) patterns. Results showed that compared with 1-step Q-P-T heat treatment, more amount of retained austenite was obtained by 2-step Q-P-T heat treatment, however, the carbides were bigger in size and the hardness was lower. Introduction Quenching and partitioning (QP) heat treatment proposed by J.G. Speer [1] is a heat treatment to produce advanced high strength steels. This heat treatment quenches the steel to a critical temperature between martensite-start (M ) and martensite-finish (M ) temp