爆炸复合Q345R基板边部裂纹的形成原因及改进措施  

A study on the causes and improvement measures of the edge cracks of the Q345R explosive composite substrate

作　　者：吴翔[1] 熊雄[1] 董富军[1] 刘小林[1] WU Xiang;XIONG Xiong;DONG Fujun;LIU Xiaolin(Xinyu Iron and Steel Group Co.,Ltd,Xinyu,338001,Jiangxi,China)

机构地区：[1]新余钢铁集团有限公司,江西新余338001

出　　处：《江西冶金》2020年第6期65-70,共6页Jiangxi Metallurgy

摘　　要：采用光学显微镜、扫描电子显微镜和能谱分析仪,对爆炸复合Q345R基板边部开裂部位进行检测分析。研究结果表明:在爆炸的高温和高压作用下,钢板心部缺陷处材料受到的力超过材料屈服强度极限产生裂纹,在冲击波的作用下,裂纹迅速扩展,部分断裂造成基板和复板无法焊合;复板界面处的合金元素快速熔化渗透到基板中,复合板界面微观组织发生变化,产生严重的加工硬化,塑性降低,超过材料的屈服极限,发生开裂。根据裂纹形成原因,制定了提高钢水纯净度、减轻板坯心部偏析、降低钢板残余应力等改进措施,提高了基板的内在质量,减少了裂纹发生率。The edge cracks of the Q345R explosive composite substrate are detected and analyzed by using optical microscope,scanning electron microscope and energy spectrum analyzer in this paper.The results show that under the high temperature and high pressure of the explosion,the force on the core defect of the steel plate exceeds the yield strength limit of the material,resulting in cracks.What’s more,under the effect of the shock wave,the cracks rapidly expand and the steel plate partially fractures,causing the substrate and the composite plate to fail to be welded.Moreover,the alloy elements at the interface of the composite plate quickly melt and penetrate into the substrate,then the microstructure at the interface of the composite plate changes,resulting in severe work hardening,plasticity reduction,which exceeds the yield limit of the material,and ultimately cause cracking.According to the causes of crack,improvement measures have been formulated,such as improving the purity of the molten steel,mitigating the central segregation of the slab,reducing the residual stress of the steel plate,etc.,which improve the internal quality of the substrate and reduce the incidence of cracks.

关 键 词：爆炸焊接 金属复合板 微观组织 裂纹 改进措施 

分 类 号：TG162[金属学及工艺—热处理] TB331[金属学及工艺—金属学]