电厂锅炉末级过热器爆管原因分析
摘要：在长期过热的运行工况下，锅炉高温过热器极易产生材料的劣化以及材料组织和性能的下降，最终引发爆管事故。通过宏观检查、布氏硬度测试、抗拉强度测试和金相组织检验对某电厂末级过热器爆管原因进行分析。结果表明，该末级过热器管由于在长期高温高压下超温运行，导致碳化物在晶界富集，晶界强度下降，在拉应力的作用下，晶界产生蠕变空洞及蠕变裂纹，使得珠光体耐热钢的持久强度和抗拉强度下降，最终产生断裂失效。
Abstract:In the long-term overheating operation condition, the boiler high temperature superheater is easy to cause the deterioration of materials and the decline of material structure and performance, and causes the pipe explosion accident. The causes of burst tube of final-stage superheater tube in a power plant boiler were analysed through macroscopic examination, Brinell hardness test, tensile strength test and metallographic structure test. The analysis results show that final-stage superheater tube operates at high temperature and pressure for a long time, resulting in the carbide enrichment at grain boundary and weaken the grain boundary strength. Under the action of tensile stress, creep cavities and creep cracks occur at grain boundary, resulting in the decrease of durable strength and tensile strength of pearlite heat-resistant steel, and finally the fracture failure occurs.
标题：电厂锅炉末级过热器爆管原因分析
title:Cause Analysis of Burst Tube of Final-Stage Superheater Tube in a Power Station Boiler
作者：俞旷,王甲安,王涛英,陈陈
authors:Kuang YU,Jiaan WANG,Taoying WANG,Chen CHEN
关键词：锅炉,末级过热器,碳化物,珠光体耐热钢,蠕变裂纹,断裂失效,
keywords:boiler,final-stage superheater tube,carbide,pearlite heat-resistant steel,creep crack,fracture failure,
发表日期：2019-04-30
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