摘要
研究不同冷变形量(0,20%和50%)对固溶态含铝奥氏体不锈钢在650℃、时效120 h后的显微组织和力学性能的影响。研究结果表明:当冷变形量由0增加至20%时,位错密度急剧增加,而当冷变形量增加到50%时,位错密度增加缓慢。在晶内,不同冷变形量的3种样品均可见NiAl析出相,其析出数量与冷变形量成正比。当冷变形量为20%时,可使NiAl相尺寸略微细化;而当冷变形量增加到50%时,可使NiAl相的尺寸略微粗化。在晶界处,3种样品均析出较多的Cr_(23)C_(6)。冷变形量分别为20%和50%的样品,晶界处Laves相和NiAl相的析出量增多,但Laves相在晶内的析出量则较少。在室温时,适当的冷变形量会使实验钢的强度显著提高,进一步加大冷变形量对强度的贡献很小,但会明显削弱实验钢塑性;高温时,50%冷变形量样品的强度比20%冷变形量的样品强度低,但塑性略有提高。综上所述,当冷变形量为20%时,合金具有良好的拉伸性能。
The effect of different cold deformation(0, 20% and 50%) on the microstructure and mechanical property evolution of a solid solution alumina forming austenitic(AFA) steel after aging at 650 ℃ for 120 h was investigated. The results show that as the amount of cold deformation increases from 0 to 20%, the dislocation density increases obviously. When the cold deformation further increases to 50%, the dislocation density increases slightly. NiAl precipitates in the grain interior for all the three aged samples. The increase of deformation level promotes the amount of NiAl precipitates. Cold deformation with 20% level can coarsen the size of NiAl phase slightly, and when the cold deformation increases to 50%, the size of NiAl phase is refined slightly. Coarse Cr_(23)C_(6)precipitates at the grain boundary in the three aged samples. The cold deformation also promotes the precipitation of the Laves phase and NiAl phase in grain boundary, but the precipitation amount of Laves phase in the grain interior is less. The room temperature strength of the sample steel increases obviously with the increase of cold deformation, while the plasticity of steel sample decreases. At high temperature, the strength of 50% cold deformed sample is lower than that of 20% cold deformed sample, but it still maintains good plasticity. In conclusion, the 20% cold deformed alloy shows good tensile property.
作者
孙钢
郑继云
周张健
SUN Gang;ZHENG Jiyun;ZHOU Zhangjian(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China;Science and Technology on Reactor Fuel and Materials Laboratory,Nuclear Power Institute of China,Chengdu 610041,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第1期61-72,共12页
Journal of Central South University:Science and Technology
基金
国家重点研发计划项目(2018YFE0116200)
国家自然科学基金资助项目(51001299)。
关键词
含铝奥氏体不锈钢
冷变形
时效
析出相
力学性能
alumina forming austenitic steel
cold deformation
aging
precipitates
mechanical property
作者简介
通信作者:周张健,博士,教授,从事能源系统用先进材料研究,E-mail:zhouzhj@mater.ustb.edu.cn。
