不同钼含量445超纯铁素体不锈钢的时效析出行为  

Aging precipitation behavior of 445 ultra-purified ferritic stainless steel with different Mo contents

作　　者：李建春[1] 贾元伟 Li Jianchun;Jia Yuanwei(Shanxi Taiyuan Stainless Steel Co.,Ltd.,Taiyuan Shanxi 030003,China)

机构地区：[1]山西太钢不锈钢股份有限公司,山西太原030003

出　　处：《金属热处理》2024年第12期163-168,共6页Heat Treatment of Metals

摘　　要：利用热力学软件Thermo-Calc分析了0.68%、1.79%和2.37%3种不同钼含量445超纯铁素体不锈钢中平衡析出相的种类,并对其进行1020℃×10 min退火及700℃/870℃×1 h时效处理,采用SEM和TEM等方法对其退火及时效后析出的第二相进行观察与研究。结果表明,Thermo-Calc计算所得平衡析出相种类与相观察分析的试验结果基本一致,时效处理后445不锈钢中析出了长条状Laves相Fe_(2)(Nb,Mo)和颗粒状(Nb,Ti)C两种不同形态的析出相,其中Laves相Fe_(2)(Nb,Mo)主要分布在晶粒内部,而(Nb,Ti)C在晶粒内部和晶界区域均有分布。不同钼含量445超纯铁素体不锈钢第二相析出的敏感性具有明显差异。随着钼含量的增加,第二相析出温度逐渐升高;相同时效温度下第二相析出量也随之增大。Types of equilibrium precipitated phases in 445 ultra-purified ferritic stainless steel with different Mo content(0.68%,1.79%and 2.37%)were analyzed by Thermo-Calc thermodynamic software.The specimens were annealed at 1020℃for 10 min and aged at 700℃/870℃for 1 h.The SEM and TEM methods were used to study the precipitation of second phases in the 445 stainless steel after annealing and aging.The results show that the types of equilibrium precipitates calculated by Thermo-Calc are basically consistent with the experimental results of microstructure observation and phase analysis.The second phases with different morphologies are precipitated in the aged 445 stainless steel,including Laves phase Fe_(2)(Nb,Mo)with strip-like shape distributing inside the grain and(Nb,Ti)C carbides with irregular granular shape presenting inside the grain and at the grain boundaries.There is remarkable difference in sensitivity of precipitated phases for the 445 ultra-purified ferritic stainless steel with different Mo contents.As the Mo content increases,the precipitation temperature of second phase rises and the amount of second phase precipitation also increases at the same aging temperature.

关 键 词：THERMO-CALC软件 铁素体不锈钢 第二相 时效 

分 类 号：TG156.1[金属学及工艺—热处理]