氨分解气氛保护退火对冷轧不锈钢带组织及硬度影响  

Effects of annealing with ammonia dissociated protective atmosphere on microstructure and hardness of cold rolled stainless steel strip

作　　者：刘伟[1] 涂益友[1] 丁建刚 杨恒[3] 蒋建清[1] 

机构地区：[1]东南大学江苏省先进金属材料高技术研究重点实验室,江苏南京211189 [2]无锡市华生精密合金材料有限公司,江苏无锡214016 [3]江苏法尔胜集团,江苏江阴214433

出　　处：《金属热处理》2009年第10期53-56,共4页Heat Treatment of Metals

基　　金：国家科技支撑计划(2007BAE51B09)

摘　　要：采用金相显微镜、扫描电镜、透射电镜等手段研究SUS304和SUS321冷轧不锈钢带经氮气气氛和氨分解气氛保护退火后的微观组织,并分析钢带截面显微硬度和退火前后含氮量的变化。结果表明,SUS321不锈钢带经气氛保护退火后,材料中氮含量明显升高,表层存在细晶区,显微硬度远高于心部。其原因是在气氛保护退火过程中,含Ti不锈钢表层发生渗氮,生成阻止高温奥氏体晶粒长大的TiN或Ti(NC)颗粒。Microstructure of SUS304 and SUS321 cold rolled stainless steel strips after annealed with N2 and ammonia dissociated atmosphere was investigated by using metallographic microscope, SEM and TEM. Microhardness of cross section and the change of nitrogen content of the strip after annealed were analyzed. The results show that after annealing ammonia with dissociated atmosphere, nitrogen content of the SUS321 steel strip increases highly ,fine grain region exists in surface layer where their micro-hardness is much higher than that of center. That is due to nitriding occured in the surface layer of Ti contained stainless steel strip during the process of annealing with ammonia dissociated protective atmosphere, and TiN or Ti（NC） nitride particles formed in the surface layer can inhibit austenite grain growth in the process.

关 键 词：冷轧不锈钢带 光亮退火 氨分解气氛 显微硬度 

分 类 号：TG156.2[金属学及工艺—热处理]