氧化风机轴断裂的失效分析与预防措施

摘要

采用金相检验、化学成分分析、力学性能测试及断口SEM检验等试验手段,结合现场情况调研对45钢氧化风机轴在使用过程中发生断裂的原因进行了分析. 结果表明:氧化风机轴的断裂形式为脆性解理断裂,金相组织为非均匀稳定的退火态组织,缺口敏感性较大. 加之氧化风机运行环境恶劣,振动和长时间超负荷运行导致在轴的表面形成疲劳裂纹最终导致轴的断裂失效. 针对上述问题提出了相关预防措施.%Metallographic examination, chemical composition, mechanical property, fracture SEM inspi-ration are used for failure analysis in the fracture of 45 steel oxidation fan shaft of power plant boiler com-bining with on-site investigation of the case of the shaft.The result indicates that the fracture mode is brittle cleavage fracture.The micro-structure is unstable annealed organization.The notch sensitivity of shaft is obviously.Combined with the harsh operating environment,vibration and overload with long time lead to the formation of fatigue cracks in the surface of the shaft.Preventive measures are put forward fi-nally.