轧辊扁头断裂失效分析

Analysis on Failure Caused by Breaking of Flat Head of Roll

借助于光学显微镜、扫描电镜检验设备,结合力学性能测定、化学成分分析等方法,对材质为25Cr2Ni4MoV的轧辊扁头进行了相关检验分析,找出轧辊扁头断裂失效原因。结果表明,扁头失效形式为起源于表面缺陷的高应力低周多源疲劳断裂,堆焊表面存在气孔缺陷是扁头产生台阶状的疲劳断裂的主要原因,扁头金相组织不均匀和基体强度不足是扁头发生疲劳断裂的重要影响因素。

With the help of such inspection equipment as optical microscope and scanning electron microscope,combined with the method such as mechanical property measurement and chemical composition analysis,the relevant inspection and analysis over the flat head of a roll made of 25Cr2Ni4MoV was carried out to find out the cause leading to the failure of the flat head.The analytical results demonstrated that the failure of the flat head was originated from the start of a high-stress low-cycle multi-source fatigue fracture caused by surface defects.And the porosity defect occurred on the build-up welding surface was the main cause leading to the step-like fatigue fracture on the flat head while inhomogeneous metallographic structure and insufficient strength of the matrix in terms of the flat head were an important influencing factor leading to the fatigue fracture of the flat head.