Effect of quenching temperature on the microstructure and mechanical properties of 30MnBNbV hot stamping steel. (13th September 2019)

• Record Type: Journal Article
• Authors: Chen, Weijian; Wang, Shuai; Zhao, Zhengzhi; Liang, Jiangtao; Guo, Jie
• Is Part Of: Materials research express. Volume 6:Number 10(2019)
• Publication Date: 2019-09-13
• Subjects: hot stamping steel -- mechanical properties -- martensite -- retained austenite; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/ab41ca
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: A low carbon steel microalloyed with Nb-V subjected to hot stamping process, then quenching to different temperatures (30 °C, 230 °C, 300 °C) followed by air cooling to room temperature was investigated. The method in this article was significantly simplified compared with the conventional quenching & tempering (QT) process. The results shown that the best comprehensive mechanical properties could be obtained at 230 °C. The yield strength (YS) and ultimate tensile strength (UTS) were 1128.8 MPa and 1768.8 MPa respectively, and the total elongation was 8.8% without much compromise. The excellent properties were attributed to a multi-morphology microstructure which consisted of large amount of martensite (block fresh martensite and lath tempered martensite) and trace carbon-enriched retained austenite. In addition, the recovery of block fresh martensite (FM) and decomposition of unstable austenite were discussed during air cooling to room temperature process.