爆炸焊接结构钢-不锈钢复合板界面的微观缺陷

Microscopic Defect at Interface of Explosion-Welded Structural Steel-Stainless Steel Composite Plate

以Q235A低碳钢,16Mn、15MnVN低合金钢等3种结构钢为基板,以304不锈钢为覆板,采用爆炸焊接方法制备了结构钢-不锈钢复合板,利用超声波探伤、扫描电镜观察、能谱检测等分析了结合界面处的微观缺陷。结果表明:爆炸焊接复合板界面处存在空洞和微缝隙缺陷,这些缺陷不能通过热轧消除;空洞处的主要成分为铁元素,与原始钢板的成分有较大差异;当爆速增大、基板材料塑性降低时,复合板界面区的微裂纹率会增加;热轧后,复合板界面的局部区域出现夹层缺陷,夹层缺陷位于覆板一侧,其成分与基板的相近。

With three structural steels of Q235 Alow carbon steel,16Mn and 15MnVN low-alloy steels,respectively,as a basal plate and 304 stainless steel as a shroud plate,the structural steel-stainless steel composite plates were prepared by explosion welding.The microscopic defects at the bonding interface were investigated by ultrasonic flaw detection,scanning electron microscopy,energy dispersive spectrometer,etc.The results show that the holes and the microgaps existed at the interface of explosion-welded composite plates,which can′t be eliminated by hot-rolling.The main element was iron in the holes and the composition was much different from that of raw steel plate.The microcrack ratio in the interface of the explosion-welded composite plate increased with the increase of the explosion speed or the reduction of the plasticity of the basal plate.After hot-rolling,some sandwich defects were found in the local interface of the composite plate,which were on the side of the shroud plate and with nearly the same composition as the basal plate.