超厚718H模具钢板表面裂纹分析  

Analysis on Surface Crack of Extra Heavy 718H Die Steel Plate

作　　者：温小园 邓深 赵贤平 Wen Xiaoyuan;Deng Shen;Zhao Xianping(Technical Center of Guangxi Liuzhou Iron and Steel Group Co.,Ltd.)

机构地区：[1]广西柳州钢铁集团有限公司技术中心

出　　处：《宽厚板》2021年第6期41-43,共3页Wide and Heavy Plate

摘　　要：针对超厚规格718H模具钢板出现的表面裂纹缺陷,利用光学显微镜、扫描电镜、能谱仪及热膨胀仪对表面裂纹产生的原因进行分析研究。结果表明:718H钢表面裂纹缺陷并非铸坯原生裂纹导致,而是由于连铸坯热送热装时,温度处于两相区,钢板体积收缩,形变量大,致使晶界拉裂,形成裂纹。为减小产生裂纹的几率,建议718H模具钢连铸坯在相变点Ar_(3)以下的温度入炉加热。In view of the surface crack defects of extra heavy 718H die steel,the causes of surface crack are analysed and studied by optical microscope,scanning electron microscope,energy spectrometer and thermal dilatometer.The results show that the surface crack defects of 718H die steel are not caused by the primary crack of the slab,but by the fact that the temperature of continuous casting slab is in the two-phase zone during hot delivery and hot charging,which leads to the volume contraction and the large deformation of the steel plate,further results in grain boundary tension fracture and formation of crack.In order to reduce the tendency of cracking,it is suggested that the continuous casting slab of 718H die steel is charged into the furnace at a temperature below phase transition point Ar_(3).

关 键 词：718H模具钢 表面裂纹 组织转变 热送热装 

分 类 号：TG142.1[一般工业技术—材料科学与工程]