长时间服役的进口锅炉T91炉管失效行为研究

针对某进口亚临界锅炉三级过热器T91炉管失效事件,通过对其进行硬度、金相组织和SEM扫描电镜分析找出导致爆管的原因,并根据高温氧化皮厚度对其进行蠕变剩余寿命评估,结果表明该段T91管材爆管类型为典型长期过热爆管,炉管长期处于较高温度运行导致组织老化严重,力学性能下降,引起材料蠕变损伤,导致长期过热爆管,经计算其蠕变剩余寿命已达到寿命极限。本文对该锅炉防止类似事故具有重要作用,并对国内其他同在二十世纪90年代开始服役的T9彳炉管具有重大的参考价值和借鉴意义。

Research on Failure Behavior of Imported Boiler T91 Furnace Tubes in Long Service

A 3RY superheater tube burst occurred on the SA213-T91 steel pipe in a long-term serviced imported boiler,several tests such as mechanical properties,metallographic observation,hardness tests and SEM scanning electron microscopy tests were conducted to find out the reasons which cause the failure.The creep residual life of the tube was evaluated according to the thickness of oxide in high temperature environment.The results showed that the tube burst type of T91 tube was typically long-term overheated burst feature.The long-term service of T91 tube at high temperatures results in serious aging of the structure,degradation of mechanical properties and creep damage of materials,which caused the failure of T91 tube.The calculated residual creep life the T91 tube was far less than 8700 hours.This research plays an important role in preventing similar accidents of the boiler,and has great reference value and reference significance for other long-term service T91 tubes.