【摘要】 用光学金相显微镜等分析手段,对用SWRM8材质制造的5.5 mm螺栓帽头开裂原因进行了分析。结果表明:SWRM8螺栓帽头开裂是线材表面线状缺陷经冷镦形成的;线状缺陷与铸坯缺陷(如纵裂纹、皮下气泡、夹渣等)以及热轧和冷拉拔过程中产生的划伤有关。更多还原

【Abstract】 Causes to the rupture of 5.5 mm bolt head out of SWRM8 are checked and analyzed by means of the optical metallographic microscope.Results show that the primary cause to the rupture of the bolt head SWRM8 is the surface defect of the wire rod occurring in the process of cold heading.The surface defect of the wire rod is closely related with the defects of the billets(such as longitudinal crack,subsurface blowhole and entrapped slag) as well as scratch taking place in the process of hot rolling and cold drawing.更多还原