北京科技大学学报2016，Vol.38Issue(3)：364-370,7.DOI:10.13374/j.issn2095-9389.2016.03.010
σ相对S32760超级双相不锈钢组织和性能的影响
Influence of σ phases on the microstructure and properties of S32760 super duplex stainless steel
摘要
Abstract
The precipitation behavior ofσphases in W-containing S32760 super duplex stainless steel was studied by aging treat-ment experiments. The morphology and chemical composition of the σ phases were investigated by scanning electron microscopy and transmission electron microscopy. The effects of the σ phases on the mechanical properties and corrosion resistance of the stainless steel were analyzed additionally. The σ phases composed of Fe- Cr- Mo- W have a tetragonal structure and abundantly precipitate at 850-1000℃ in the stainless steel with quite high strength and hardness and extremely poor plasticity, for example, the elongation is lower than 4. 0%. There are still a few ofσphases at 1050℃, though the elongation increases to 31. 1%, the values of impact tough-ness are discrete, and the average impact energy is low. Until 1080℃, the σ phases completely dissolve to the matrix. The tensile strength and the elongation are 640 MPa and 35. 5%, and the longitudinal and the transverse impact energies averagely reached to 217 J and 110 J, respectively. As the treatment temperature increasing, the pitting potential ( Eb ) improves, and the mass loss rate of pitting corrosion decreases. The pitting potential of the stainless steel treated at 1080℃ is up to 1246 mV, while the mass loss rate decreases only to 0. 005-0. 007 g·m-2·h-1 when being soaked in a 3. 5% NaCl solution at 50℃.关键词
不锈钢/热处理/析出相/微观组织/力学性能/耐腐蚀性Key words
stainless steel/heat treatment/precipitates/microstructure/mechanical properties/corrosion resistance分类
矿业与冶金引用本文复制引用
李国平,裴海祥,李建春,张寿禄..σ相对S32760超级双相不锈钢组织和性能的影响[J].北京科技大学学报,2016,38(3):364-370,7.基金项目
国家科技支撑计划资助项目(2012BAE04B01) （2012BAE04B01）
国家高技术研究发展计划资助项目(2015AA034301) （2015AA034301）
