45钢垫块开裂失效机制分析

Analysis of cracking failure Mechanism of 45 Steel cushion block

采用金相显微镜、布洛维硬度计、火花直读光谱仪等设备对45钢垫块开裂件进行了宏观形貌观察、显微组织分析、硬度检测以及成分分析。结果表明,造成垫块失效的裂纹类型为淬火裂纹,由于材料内部存在大量夹杂物,夹杂物在破坏基体连续性的同时造成局部应力集中,增加了材料的淬火开裂倾向,是垫块失效的主要原因。

The macroscopic morphology observation,micro-structure analysis,hardness detection and composition analysis of the cracked parts of 45 steel cushion block have been carried out by metallographic microscope,Blovi hardness tester,spark direct reading spectrometer and other equipment.The results show that the type of crack which causes the failure of the cushion block is quenching crack.Due to the existence of a large number of inclusions in the material,the inclusions destroy the continuity of the matrix and cause local stress concentration,while increases the quenching cracking tendency of the material,which is the main reason for the failure of the cushion block.