Hot Working Characteristic of Superaustenitic Stainless Steel 254SMO

• Published in: Acta metallurgica sinica : English letters Vol. 27; no. 2; pp. 313 - 323
• Main Authors: Pu, Enxiang, Zheng, Wenjie, Xiang, Jinzhong, Song, Zhigang, Feng, Han, Zhu, Yuliang
• Format: Journal Article
• Language: English
• Published: Heidelberg The Chinese Society for Metals 01.04.2014; Springer Nature B.V
• Subjects: Austenitic stainless steels; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Corrosion resistance; Deformation; Domains; Dynamic recrystallization; Electrolytes; Energy dissipation; Flow mapping; Flow stability; Grain size; Hot working; Instability; Interfaces; Materials Science; Mathematical analysis; Metallic Materials; Microstructure; Nanotechnology; Organometallic Chemistry; Potassium; Power dissipation; Process mapping; Sigma phase; Sigma phase precipitation; Spectroscopy/Spectrometry; Stability; Stainless steel; Stainless steels; Strain rate; Temperature; Titanium alloys; Transmission electron microscopy; Tribology; 加工特性; 地图显示; 应变速率; 温度范围; 热变形特性; 等温压缩试验; 组织观察; 超级奥氏体不锈钢; Hot deformation; Processing map; 254SMO; Superaustenitic stainless steel
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-014-0047-1

Abstract Hot deformation characteristic of superaustenitic stainless steel 254SMO has been studied by isothermal compression testing in the temperature range of 950-1,200 ℃ and strain rate range of 0.01-10 s^-1. The activation energy of 496 kJ/mol was calculated by a hyperbolic-sine type equation over the entire range of strain rates and temperatures. In order to obtain optimum hot working conditions, processing maps consisting of power dissipation map and instability map were constructed at different strains. The power dissipation map exhibits two domains with relatively high efficiencies of power dissipation. The first domain occurs in the temperature range of 990-1,070 ~C and the strain rate range of 0.01-0.1 s^-1. Microstructure observation in this domain indicates the partial dynamic recrystallization （DRX） accompanied with precipitation of tetragonal sigma phase. The second domain occurs in the temperature range of 1,140-1,200 ℃ and the strain rate range of 0.01-1 s^-1 with a peak efficiency of power dissipation of 39%, and in this domain, the microstructure observation reveals the full DRX. The instability map shows that flow instability occurs at the temperatures below 1,140 ℃ and the strain rates above 0.1 s^-1.