Simultaneously Improving Mechanical Properties and Stress Corrosion Cracking Resistance of High-Strength Low-Alloy Steel via Finish Rolling within Non-recrystallization Temperature

• 作者: Hongchi Ma Baijie Zhao Yi Fan Kui Xiao Jinbin Zhao Xuequn Cheng Xiaogang Li
• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2021,（4）
• 页码范围: 565-578
• 页数: 14页
• 语种: 英文

摘要

The effect of hot rolling process on microstructure evolution,mechanical properties and stress corrosion cracking (SCC) resistance of high-strength low-alloy (HSLA) steels was investigated by varying the finish rolling temperature (FRT) and total rolling reduction.The results revealed granular bainite with large equiaxed grains was obtained by a total rolling reduction of 60％ with the FRT of 950 ℃ (within recrystallization temperature Tr).The larger grain size and much less grain boundaries should account for the relatively lower strength and SCC resistance.A larger rolling reduction of 80％ under the same FRT resulted in the formation of massive martensite-austenite (M/A) constituents and resultant low ductility and SCC resistance.In contrast,a good combination of strength,ductility and SCC resistance was obtained via 80％ rolling reduction with the FRT of 860 ℃ (within non-recrystallization temperature Tnr),probably because of the fine grain size and M/A constituents,as well as a high density of grain boundary network.