某电厂一锅炉送风机在投入运行较短时间内即发生叶片断裂事故, 严重影响了电厂的安全经济运行。通过化学成分分析、金相检验、力学性能测试、断口分析和能谱微区成分分析等方法对叶片断裂的原因进行了分析。结果表明: 导致叶片断裂的主要原因是叶片质量不合格, 叶片上存在着十分严重的裂纹类原始缺陷; 另叶片材料化学成分不合格,存在较多的铸造疏松缺陷,塑性和韧性较差等也是导致其早期断裂的原因。

The blades of a forced draft fans in one power plant fractured after short time service, which seriously impacted the safe and economic operation of power plant. Through a set of tests of chemical compositions analysis, metallographic examination, mechanical properties test, fracture analysis and energy spectrum analysis, fracture reasons of the blades were analyzed. The results show that the main cause of failure was that the quality of blades was defective and there were serious crack-like original defects on the blades. And the unqualified chemical compositions, many casting porosity defects and poor plasticity and toughness of material of the blades were also factors that resulted in the fracture of blades.