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针对某公司的45钢摩擦焊杆,采用材料结构分析技术研究了热处理对接头组织性能的影响。结果表明,热处理前焊接接头为先共析铁素体+珠光体+魏氏体的粗大组织,母材为珠光体和沿晶界铁素体组织,焊缝的显微硬度最大,热影响区其次,母材最小,拉伸试样断裂位置在母材;经过正火、淬火和回火的热处理后,焊接接头组织变得细小而均匀,为回火索氏体+贝氏体+少量沿晶界铁素体混合组织,焊缝和母材的显微硬度基本接近,拉伸试样断裂位置在正火区与不完全正火区的交界处,冲击断裂面平直,呈现脆性断裂特征,为准解理+二次裂纹+撕裂状韧窝+夹杂物条带状。
Aiming at the 45 steel friction welding rod of a company, the influence of heat treatment on the microstructure and properties of the joint was studied by the method of material structure analysis. The results show that the welded joints before the heat treatment are the pro-eutectoid ferrite + pearlite + Westem body coarse structure, the parent material is pearlite and grain boundary ferrite, the weld microhardness is the largest, heat-affected zone Second, the minimum base metal, tensile specimen fracture location in the base metal; after normalizing, quenching and tempering heat treatment, the welded joints become small and uniform, for the tempered sorbite + a small amount of bainite The grain boundary ferrite mixed microstructure, weld and base metal microhardness is basically close to the tensile specimen fracture location in the normalizing zone and incomplete normalizing zone junction, the impact fracture surface is flat, showing brittle fracture characteristics , As the solution to the second crack + tearing dimples + inclusions strip.