16Mn钢焊接件疲劳裂纹萌生与扩展观察

The Observations on the Fatigue Crack Initiation and Propagation of 16Mn Steel Welded Structure

该文对 16Mn钢对焊接头的焊缝及热影响区 (HAZ)中疲劳裂纹的萌生与扩展机理进行了研究。结果发现 ,疲劳裂纹的萌生与扩展与铁素体组织有关 ,由于焊接热影响区显微组织的不均匀性 ,使疲劳裂纹的扩展机制具有某些特殊性。疲劳裂纹扩展阶段裂纹尖端附近为形成于铁素体晶粒内的位错胞及亚晶。在疲劳断裂的各个阶段 。

The fatigue crack initiation and propagation mechanism of 16Mn steel welded structure was studied in this paper.The fatigue crack initiation and propagation have relation to ferrite structure.The fatigue crack propagation mechanism is characterized by the non homogeneous microstructure in heat affected zone (HAZ).Dislocation cell and sub grain formed in ferrite grain are found at the stage of fatigue crack propagation in the area of crack tip.The fracture mechanism is changed at different stages of fatigue fracture.