高氮奥氏体不锈钢层片结构热处理调整

Heat treatments for modification upon the lamellar structures of high-nitrogen austenitic stainless steel

以0Cr21Mn17Mo2NbN高氮奥氏体不锈钢为实验材料,经1 140℃和10h固溶处理后,在750、850、950℃下进行不同保温时间时效处理,然后经1 020℃分别保温2、4h后水淬。实验结果表明,相同的保温时效时间内,850℃下析出最为明显。同一时效温度下,随保温时间延长,胞状析出物由晶界向晶内生长,形状呈层片状、条状、短棒状及颗粒状;850℃时效8、16h后经1 020℃保温4h,析出物球化现象比较明显。随着保温时间延长,硬度不断降低。

The high-nitrogen austenitic stainless steel 0Cr21Mnl7Mo2NbN was solution treated at 1 140 ℃ for 10 hours, and again aged at 750, 850 and 950℃ respectively, and further modified by heat treatments at 1 020℃ for 2 hours and 4 hours and then quenching in water. The experimental results show that the precipitation of nitrides is more obvious at 850℃. At same temperature, cellular precipitation develops from grain boundaries into grain center with flake, short rod and particle of shapes. Particle structures appear in nitride flakes with 8-hour and 16-hour of aging treatments at 850℃ and 4-hour of treatment at 1 020℃. The hardness of the steal decreases with the increase of time at 1 020℃.