Effect of zirconium on inclusions and mechanical properties of China low activation martensitic steel

• 作者: Guo-xing Qiu Dong-ping Zhan Lei Cao Hui-shu Zhang
• 来源期刊: 钢铁研究学报（英文版）
• 年，卷（期）: 2021,（9）
• 所属期刊栏目: ORIGINAL PAPERS
• 页码范围: 1168-1179
• 页数: 12页
• 语种: 英文

摘要

The effects of 0.01–0.11 wt.％Zr on the inclusions, microstructure, tensile properties, and impact toughness of the China low activation martensitic steel were investigated. Results showed that Zr exhibits good deoxidation and desulfurization abilities. The scanning electron microscope was used to examine the inclusions in the ingots. The main inclusions in the alloys were Zr–Ta–O, Zr–O, and Zr–O–S. However, some blocky Zr-rich inclusions appeared in Zr-2 and Zr-3 alloys. Typical martensitic structures were observed in the alloys, and average prior austenite grain sizes of 21.1, 15.7, and 14.8μm were obtained for Zr-1, Zr-2, and Zr-3 steels, respectively. However, increasing Zr content of the steels deteri-orated their mechanical property, owing to the blocky inclusions. The alloy with 0.01％Zr resulted in excellent mechanical properties due to the fine inclusions and the precipitation of Zr3V3C carbides. Values of 576 and 682 MPa were obtained for the yield strength and ultimate tensile strength of Zr-1 alloy, respectively. Furthermore, the ductile–brittle transition temperature of the alloy decreased to-85 ℃.