1000MW超超临界锅炉屏式过热器爆管原因分析  

Cause Analysis of Tube Explosion of Screen Superheater of 1000MW Ultra Supercritical Boiler

作　　者：周公文 ZHOU Gongwen

机构地区：[1]泰安市特种设备检验研究院,泰安市271000

出　　处：《化工装备技术》2022年第5期25-27,共3页Chemical Equipment Technology

摘　　要：某1000 MW超超临界锅炉屏式过热器管(12Cr1MoVG)弯头部位发生爆管事故。对爆口部位进行宏观检查、化学成分分析、金相组织检验和硬度检验,根据试验结果可知,爆管的原因是该弯头处存在氧化皮堵塞问题,使该部位介质流通面积减小,不能得到有效冷却,造成管壁长期超温运行,加速氧化皮的生成与脱落,使微观组织的严重球化,导致弯头背弧面处强度降低严重,最终在弯头背弧面拉应力最大部位发生纵向开裂。A tube burst occurred at the elbow of a 1000MW ultra-supercritical boiler screen superheater tube(12Cr1MoVG).Macroscopic inspection,chemical composition analysis,metallographic structure inspection and hardness inspection were carried out on the blast site.According to the test results,it was concluded that the reason for the tube burst at the elbow of the screen type superheater was that there was a problem of oxide scale clogging at the elbow,which reduced the medium flow area of this part,and this part could not be effectively cooled.The long-term over-temperature operation of the pipe wall accelerated the formation and shedding of oxide scale and the serious spheroidization of the microstructure,resulting in a serious decrease in the strength of the back camber of the elbow,and eventually longitudinal cracking occurs at the highest tensile stress on the back camber of the elbow.

关 键 词：屏式过热器管 氧化皮 超温运行 纵向开裂 

分 类 号：TG113[金属学及工艺—物理冶金]