工程科学学报Issue(5)：60-67,8.DOI:10.13374/j.issn2095-9389.2015.05.010
改进310奥氏体不锈钢长期时效后的组织与性能
Microstructures and mechanical properties of a new 310 austenitic stainless steel during long term aging
摘要
Abstract
The microstructures and mechanical properties of a modified 310 austenitic stainless steel during isothermal aging at 700℃ were investigated by using scanning electron microscopy ( SEM) and transmission electron microscopy ( TEM) , tensile testing at ambient temperature and 700℃, and micro-hardness testing. It was found that massive block ( Cr,Fe,Mo) 23 C6 , ( Cr,Fe) 23 C6 car-bides,σ-phase and a small quantity ofχ-phase formed on grain boundaries and within grains in the tested steel after aging at 700℃ for 1000 h. Precipitates significantly strengthened the mechanical properties of the tested steel at room temperature. The strength increased and the hardness raised by 20 Hv, while the elongation still remained above 30%. However, at high temperature, the effect of precip-itation strengthening was weakened, and the ductility slightly decreased. Fracture surface and cross-sectional microstructural analysis after tensile testing showed that the high temperature tensile fracture mode after aging for 1000 h was ductile fracture; neither cracks nor holes were observed;but the room temperature tensile fracture was brittle, and there were some cracks and holes inσ-phase near the fracture. Finally, from the ductile-brittle transition ofσ-phase and the difference in strength between room temperature and 700℃, this article discussed the reason for crack and hole forming in the stretching process at room temperature as well as the different effects of aging on the mechanical properties at room temperature and high temperature.关键词
奥氏体不锈钢/时效/析出相/显微组织/力学性能Key words
austenitic stainless steel/aging/precipitates/microstructure/mechanical properties分类
矿业与冶金引用本文复制引用
孙红英,周张健,王曼,邹雷,李少夫..改进310奥氏体不锈钢长期时效后的组织与性能[J].工程科学学报,2015,(5):60-67,8.基金项目
国家重点基础研究发展计划资助项目(2007CB209800) （2007CB209800）
