Precipitation Behavior of σ Phase in Ultra-Supercritical Boiler Applied HR3C Heat-Resistant Steel

论文摘要

The precipitation kinetics of σ phase in commercial HR3C heat-resistant steel during aging at 650–800 °C was studied in the paper. Through morphology, composition and structural analyzing on the second phase in the HR3C steel, it was confi rmed that the precipitations after aging were mainly NbCrN, M23C6 and FeCr type σ phase. The time-dependent mass change of the three precipitated phases showed that the linearly increased σ phase after aging at 750 °C–2000 h was transformed from NbCrN phase or M23C6 phase. According to the calculation on the volume fraction of electrolytically dyed σ phase, the time–temperature transformation（TTT） curve for σ phase at 1 vol% in two kinds of commercial HR3C steel（different in grain size） was obtained and analyzed. The nose of the TTT curve was located at around 750 °C for the two kinds of HR3C steel, and the larger grain size HR3C steel displayed a inhibit effect on the precipitation of σ phase. The impact energy of the HR3C steel after aging at 700 °C decreased obviously with the fracture mechanism changing from ductile fracture to intergranular brittle fracture, which was considered to be related to the density of σ-brittle phase after aging.

论文目录

• 1 Introduction
• 2 Experimental Method and Material
• 3 Results and Discussion
• 4 Conclusions

文章来源

类型: 期刊论文

作者: Tie-Shan Cao,Cong-Qian Cheng,Jie Zhao,Hui Wang

来源: Acta Metallurgica Sinica(English Letters) 2019年11期

年度: 2019

分类: 工程科技Ⅰ辑

专业: 金属学及金属工艺

单位: School of Materials Science and Engineering , Dalian University of Technology,State Key Laboratory of Structural Analysis for Industrial Equipment , Dalian University of Technology

基金: financials support by National Natural Science Foundation of China (No. U1610256),the National High Technology Research and Development Program of China (The 863 Program) (No. 2015AA034402),the Dalian University of Technology Fundamental Research Fund (No. DUT17RC(3)010)

分类号: TG142.73

页码: 1355-1361

总页数: 7

文件大小: 4139K

下载量: 34