超临界机组锅炉高温再热器变形及爆管原因分析  

Reason analysis on deformation and tube burst of high temperature reheater for a supercritical boiler

作　　者：肖国华[1] 冯琳杰[2] 田晓[1] 曹剑锋[1] 杨百勋[1] 

机构地区：[1]西安热工研究院有限公司,陕西西安710032 [2]华能平凉电厂,甘肃平凉744000

出　　处：《热力发电》2013年第10期111-115,共5页Thermal Power Generation

摘　　要：针对某超临界机组锅炉高温再热器T91前屏爆管及出口TP347H直管变形的问题,通过对其进行宏观形貌、化学成分、金相组织、硬度、室温和高温拉伸性能等分析。结果表明:前屏爆管为焊接时采用规范的线能量较高、焊后热处理不当、焊接结构设计不合理导致母材与吊板衔接的角焊缝出现裂纹所致,管系结构设计引起的管屏应力也起到了一定的促进作用;高温再热器出口直管段变形与管屏拘束和TP347H材料高温强度较低有关。Tube burst and straight tube deformation occurred on T91 steel pipes in front plane and TP347H steel pipes at outlet of the high temperature reheater in a power plant,respectively.Thus,several tests were conducted to find out the reasons,such as field investigation,macro-morphology observation,chemical composition analysis,metallographic observation,hardness tests,room-temperature and high temperature tensile tests.The results showed that the tube burst was due to crack in fillet weld where the hanger plate was connected to the base material.The crack was induced by high hardness of fillet weld of the hanger plate,high welding criterion,improper welding structure design and PWHT process.Moreover,it was also promoted by tube panel stress related to the tube system structure design.The curvature of the straight tube at outlet of the high-temperature reheater was related to the tube panel constraint and low high-temperature strength of TP347H steel.

关 键 词：超临界机组 高温再热器 爆管 变形 T91 TP347H 焊缝 线能量 

分 类 号：TG457.6[金属学及工艺—焊接]