Tempering Characteristics of Laser Surface-melted Layer of High Chromium Steel
The precipitation of secondary carbides in the laser melted high chromium steels during tempering at 450, 560 and 650℃ has characterized and carbides are identified in detail using TEM. Laser melted layer consists of austenitic dendrites and interdendritic M23C6 carbides. The austenite has such a strong tempering stability that it remains unchanged at temperature below 400℃ and the secondary hardening phenomenon starts from 450℃ to the maximum value at 560℃. After tempering at 450 fine M ℃ 23C6 carbides precipitate from the supersaturated austenite preferentially. While tempering below 560 , the secondary harden ℃ ing simultaneously results from the martensite phase transformation and the precipitation of carbides as well as dislocation strengthening within a refined microstructure. Moreover, the formation of the ferrite matrix and large quality of coarse lamellar M3C carbides after tempering at 650℃ contributes to the decrease of hardness. Moreover, the formation of the ferrite matrix and large quality of coarse lamellar M3C carbides after tempering at 650℃ contributes to the decrease of hardness.
Li Meiyan Wang Yong Han Bin Song Lixin
College of Electromechanical Engineering, China University of Petroleum, Dongying, 257061, China Offshore Oil Engineering (Qingdao) Co., Ltd., Qingdao, 266520, China
国际会议
桂林
英文
1-7
2010-11-16（万方平台首次上网日期，不代表论文的发表时间）