热轧后分段冷却对Ti微合金化低碳钢显微组织和力学性能的影响  

Effect of Staged Cooling after Hot-Rolling on Microstructure and Mechanical Properties of Titanium Micro-alloyed Low-Carbon Steel

作　　者：王承剑 王海波[1] 彭欢[1] 石东亚 余宣洵 WANG Chengjian;WANG Haibo;PENG Huan;SHI Dongya;YU Xuanxun(Technology Center,Maanshan Iron and Steel Co.,Ltd.,Maanshan Anhui 243000,China)

机构地区：[1]马鞍山钢铁股份有限公司技术中心,安徽马鞍山243000

出　　处：《上海金属》2023年第4期51-55,共5页Shanghai Metals

摘　　要：对以微量(质量分数为0.08%~0.09%)钛合金化的低碳钢板热轧后分别空冷至600、650和700℃再快速冷却至卷取温度。检测了钢卷的显微组织和力学性能。结果表明:随着热轧后开始空冷温度的升高,钢卷的显微组织从少量贝氏体+铁素体转变为少量珠光体+铁素体;钢卷中Ti析出物主要为弥散的纳米级TiC和亚微米级Ti(C,S);随着热轧后开始快速冷却温度从600℃提高至650℃,钢卷的强度提高了16.5%,析出物尺寸增加了3.75 nm,体积分数增加了0.215%;随着热轧后开始快速冷却温度从650℃升高至700℃,钢卷的强度下降了9.7%,析出物尺寸增大了9 nm,体积分数仅增加了0.035%;650℃为Ti析出物的最佳析出温度。Low-carbon steel plate alloyed with a minute amount(mass fraction of 0.08%to 0.09%)of titanium was air cooled to 600,650 and 700℃and then rapidly cooled to coiling temperature after hot-rolling,respectively.Subsequently,the steel coils were tested for microstructure and mechanical properties.The results showed that(a)as temperature at the start of rapid cooling after hot-rolling increased,the microstructure of the steel coil changed from a small amount of bainite plus ferrite to a small amount of pearlite plus ferrite;(b)Ti precipitates in the steel coil were predominantly nano-sized TiC and submicron-sized Ti(C,S);(c)with the rise in temperatures at the start of rapid cooling after hot-rolling from 600 to 650℃,the steel coil increased by 16.5%in strength,by 3.75 nm in size of the precipitates and by 0.215%in volume fraction of the precipitates;(d)as temperature at the start of rapid cooling after hot-rolling increased from 650 to 700℃,the steel coil decreased by 9.7%in strength,increased by 9 nm in size of the precipitates and by 0.035%in volume fraction of the precipitates;and(e)650℃was an optimal deposition temperature for Ti precipitates.

关 键 词：分段冷却 析出强化 显微组织 力学性能 

分 类 号：TG335.1[金属学及工艺—金属压力加工]