渗铝复合激光冲击对321不锈钢腐蚀疲劳性能的影响  

Effect of Aluminizing and Laser Shock Peening on Corrosion Fatigue Properties of 321 Stainless Steel

作　　者：李微[1,2] 肖国源 陈辉涛 杨蕾 张圣德 LI Wei;XIAO Guoyuan;CHEN Huitao;YANG Lei;ZHANG Shengde(School of Energy and Power Engineering,Changsha University of Science&Technology,Changsha 410114,China;Hunan Province 2011 Collaborative Innovation Center of Clean Energy and Smart Grid,Changsha 410114,China;Japan Electric Power Central Research Institute,Tokyo 240-0196,Japan)

机构地区：[1]长沙理工大学能源与动力工程学院,长沙410114 [2]清洁能源与智能电网湖南省2011协同创新中心,长沙410114 [3]日本电力中央研究所,东京240-0196日本

出　　处：《中国表面工程》2022年第2期140-151,共12页China Surface Engineering

基　　金：国家自然科学基金(51675058,52075048);湖南省创新计划(2018RS3073);湖南省教育厅优秀青年(21B0304);长沙理工大学双一流科学研究国际合作拓展(2019IC15)资助项目。

摘　　要：针对聚焦型太阳能热发电换热管材料在熔融铝硅环境中易发生腐蚀疲劳失效的问题,采用粉末包埋渗铝和激光冲击对AISI 321不锈钢进行表面改性,研究其熔融铝硅环境下腐蚀疲劳性能。结果表明,渗铝钢表面形成以FeAl金属间化合物为主的渗层,尽管能够有效地隔离基体和腐蚀介质,但是作为疲劳裂纹的形核源,会导致腐蚀疲劳寿命降低40%;经不同功率密度的激光冲击强化处理后,渗铝钢表面硬度显著提高,延缓了疲劳裂纹萌生,提升了耐蚀性,降低了腐蚀损伤的影响,疲劳损伤占据主导地位,使得渗铝钢腐蚀疲劳寿命提高100%~200%。Aiming at the problem on corrosion fatigue failure of heat exchange tube material for Concentrating solar thermal power generation in molten aluminum silicon environment, surface modification with powder embedded aluminum and laser shock technology is applied in AISI 321 stainless steel, and the corrosion fatigue performance under molten aluminum-silicon environment is investigated. The results show that the aluminized layer mainly composed of FeAl intermediate compound, although can effectively protect substrate from corrosive medium, but as a fatigue crack nucleation source, can lead to corrosion fatigue life reduced by 40%.The surface hardness of aluminized steel is significantly improved after laser shock strengthening treatment with different power densities, which delays fatigue crack initiation, improves corrosion resistance and reduces the influence of corrosion damage, thus resulting in fatigue damage playing a dominant role, which increases the corrosion fatigue life of aluminized steel by 100%-200%.

关 键 词：AISI 321不锈钢 渗铝 激光冲击 腐蚀疲劳 

分 类 号：TG156[金属学及工艺—热处理] TB114[金属学及工艺—金属学]