Apparent morphology and structure of martensite in ultrahigh carbon steel

作者：Zhang Zhan Ling^*; Liu Yong Ning; Zhang Ke Ke; Sun Jun Jie; Xia Qi; Gao Li Hua

来源：Transactions of Materials and Heat Treatment, 2010, 31(9): 33-36.

• Austenitizing
• Austenitizing temperature
• Carbide particles
• Dislocation
• High density
• High temperature
• Lath martensite
• Pile-ups
• Quenched steel
• Sub-structures
• Submicron
• Ultrahigh carbon steel

Research was done on morphology and structure of martensite developed in an ultrahigh carbon steel containing 1.6 wt% carbon. It is shown that significant changes in microstructure with the different austenitizing temperature occur for the quenched steel. Coarse twin martensite forms by austenitizing at high temperature. In contrast, the microstructure consisting of submicron lath, jujube-stone like martensite and some fine twin martensite, as well as undissolved cementite is observed for the steel austenized at lower temperature. Three dimensional jujube-stone like martensite with the sub-structure of high density dislocations is confirmed by the observation of high resolution electron microscopy (HREM). It is suggested that the dissolution of carbide particles lags behind the ferrite to austenite transformation when the steel is being austenitized. Dislocation pile-ups form at the original positions where carbide particles are dissolved. During quenching, martensite nucleates at dislocation pile-ups, and grows and thickens through the mechanism of dislocations moving, and finally the lath martensite and jujube-stone like martensite form.

• 出版日期2010
• 单位河南大学