陶瓷衬垫单面焊接接头的韧性断裂行为研究

Study on ductile fracture behavior of welded joint of one side welding with ceramic backing

采用拉伸试验和电子显微技术研究了CO2 气体保护陶质衬垫单面焊接接头在不同三轴应力作用下裂纹起始、扩展特性 .测定了接头各区的临界空穴扩张比 (Rc/R0 ) ,讨论了 (Rc/R0 )的统计本质及接头各区的宏观断裂韧性参数VGC,并与双面焊接接头进行了比较 .研究结果指出 ,不同应力状态下 ,单面焊接接头焊缝中空穴主要在邻近衬垫成形面一侧形核、扩展 ,接头各部位的临界空穴扩张比服从正态分布 .双面焊接接头中焊缝、熔合区的VGC 值较高 ,而单面焊接接头中 ,热影响区的VGC

The characteristics of crack initiation and propagation of welded joint of one side welding(OSW) of CO\-2 shielded and ceramic backing under various stress states have been investigated by use of tensile experiment and electronic microscope technology. The critical void growth ratio and fracture toughness V \-\{GC\} of welded joints have been measured; the comparisons with base metal and welded joint of welding by both sides(WBS) have been made. The research results show that voids mainly nucleate and growth in the side of back weld in the vicinity of ceramic backing. The critical void growth ratios of welding zones are obedient to normal distribution. The V \-\{GC\} of weld and welding fusion zone of welded joint of OSW are lower than those of WBS; but the V \-\{GC\} of heat affected zone(HAZ) of OSW is higher than that of WBS.