600MW超临界机组屏式过热器管爆管分析
摘要：通过对爆管样品的宏观形貌分析、化学成分分析、硬度检验、金相组织检验和扫描电镜分析,对某超临界机组T91材质的屏式过热器爆管原因进行分析。结果表明,爆管试样硬度偏低,这与显微组织的变化相关。T91钢的正常供货组织应为回火马氏体,而爆管样品爆口处的金相组织显示马氏体板条位向消失,演变为铁素体和于晶界处析出的颗粒较大的碳化物。屏式过热器管超温服役,导致材料组织老化,综合力学性能下降,在高温高压蒸汽作用下发生失效,造成泄漏。
Abstract:The burst cause of a platen superheater tube of T91 steel in certain supercritical units was ana-lyzed by macroscopical morphology, chemical composition, hardness test,OM and SEM observation using the speci-mens exploded platen superheater tube.Results show a low hardness of the failed tube which is related to the micro-structure transformation.The metallographic structure of T91 steel is tempered martensite, while the metallographic struc-ture of the exploded tube doesn't show any martensite at all.The martensite lath is evolved into ferrite and coarsen carbides precipitated at grain boundry.The overheat opera-tion of superheater tube causes the microstructure degrada-tion and the decrease of mechanical properties, and finally causes the leakage of platen superheater tube under the condition of high temperature and pressure steam.
标题：600MW超临界机组屏式过热器管爆管分析
title:Burst Analysis on Platen Superheater Tube of 600MW Supercritical Units
作者：白佳
authors:BAI Jia
关键词：超临界锅炉,屏式过热器,T91钢,爆管,
keywords:supercritical units,platen superheater tube,T91 steel,burst tube,
发表日期：2017-10-30
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