800 MPa级含Ti高强钢铸坯断裂的原因  

Cause of cracking of 800MPa grade Ti-added high strength steel cast slab

作　　者：马玉喜[1] 段小林[2] 刘静[2] 郭斌[1] 陶军晖[1] 杜明[1] 

机构地区：[1]武汉钢铁(集团)公司研究院,湖北武汉430080 [2]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《钢铁研究学报》2016年第2期51-56,共6页Journal of Iron and Steel Research

摘　　要：通过高温热塑性试验,借助光学显微镜、透射电镜对某钢厂生产的800MPa级高强钢铸坯开裂原因进行了研究,并提出了改进措施。研究结果表明:铸坯开裂形式为"角部开裂";其主要原因是连铸后铸坯缓冷不充分,造成铸坯角部与其内部温度差异较大,在组织变化和热应力的双重作用下导致裂纹萌生,并进一步扩展为"角部开裂"。连铸后采用扣罩缓冷措施可解决铸坯开裂问题。The cause of cracking of 800 MPa grade high strength steel cast slab was studied by hot plasticity test,optical microscope（OM）and scanning electron microscope（SEM）.The improvement measures were proposed.The results show that cracking form of the cast slab is ＂crack at corner＂.The slow cooling of the cast slab is not sufficient,which leads to a large difference of temperature between the corner and inner of the cast slab.Change of microstructure and thermal stress cause crack and then extend it into ＂crack at corner＂.Slow cooling under cover after continuous casting could solve the cracking problem of the cast slab efficiently.

关 键 词：高强钢 铸坯开裂 热应力 缓冷 

分 类 号：TG115[金属学及工艺—物理冶金]