燃气轮发电机转子离心风扇开裂失效分析  

Cracking Failure Analysis of Rotor Impeller of Gas Turbine Generator

作　　者：李应明 曹金齐 

机构地区：[1]东方电气东方电机有限公司,四川德阳618000 [2]上海电气电站设备有限公司发电机厂,上海200240

出　　处：《东方电气评论》2018年第1期35-38,共4页Dongfang Electric Review

摘　　要：针对国内某燃机电厂燃气轮发电机转子离心风扇发生开裂失效问题,对风扇切片进行化学成分和机械性能检测,及对风扇断口进行低倍与微观分析,同时结合对该风扇进行有限元强度分析,综合分析风扇开裂失效形成的原因。该风扇系铸造成形,材质为不锈钢GX4CrNi13-4。综合检验结果表明,风扇的外环内圆表面在铸造成形过程中有较大面积补焊区,补焊区内存在微裂纹等缺陷导致应力集中。在发电机组运行时的拉应力和起停机的交变应力作用下,引起风扇微裂纹的进一步扩展,最终开裂失效。Cracking occurres in the centrifugal impeller of gas turbine generator rotor of a power plant. The chemical composition,mechanical properties testing and fracture micro-macro analysis, are immediately conducted and finite element strength analysis is made. The causes of cracking failure are comprehensively analyzed. Material used for cast impeller is GX4CrNi13-4 stainless steel.The comprehensive investigation results indicated that there is stress concentration at the repair welding zone where micro-cracks are over-looked in the interior surface of the impeller outer ring during casting process. Under the tensile stress from the unit run-time and the alternating stress from unit start-ups and shutdowns, further expansion of micro-cracks results in final cracking failure.

关 键 词：燃气轮发电机 离心式风扇 铸造 开裂失效分析 

分 类 号：TK474.72[动力工程及工程热物理—动力机械及工程]