摘要
因利用小时数下降,某机组启停次数及停备用时间增加,在运行过程中水冷壁发生脆性爆管,通过金相组织、垢量分析、垢成分分析等试验方法,对水冷壁管进行取样分析。结果表明:机组长期停备用产生腐蚀,加之冷态启动期间水汽控制不良,造成水冷壁垢量偏大;锅炉运行期间,炉水在垢层下浓缩产生酸性环境,水冷壁管内壁发生垢下腐蚀,造成金属材质脱碳产生CH_(4),高压CH_(4)使水冷壁发生微裂纹,造成氢损伤,最终引起水冷壁失效爆管。
Due to the decrease in the number of utilization hours,the number of start-stop times and the stop standby time of a unit increase,and brittle bursts occur on the water-cooled wall during operation,and the water-cooled wall pipe is sampled and analyzed by metallographic structure,scale quantity analysis,scale composition analysis and other test methods.The results show that the long-term shutdown of the unit produces corrosion,coupled with poor water vapor control during cold start-up,resulting in a large amount of water wall scale.During the operation of the boiler,the furnace water is concentrated under the scale layer to produce an acidic environment,the inner wall of the water-cooled wall pipe is corroded under the scale,resulting in the decarburization of metal materials to produce CH_(4),and the highpressure CH_(4) causes microcracks in the water-cooled wall,causing hydrogen damage,and finally causing the water-cooled wall to fail and burst the pipe.
作者
于洋
刘青华
YU Yang;LIU Qing Hua(Huadian Electric Power Research Institute Co.,Ltd.Jinan 250003,China)
出处
《全面腐蚀控制》
2024年第5期135-138,共4页
Total Corrosion Control
关键词
长期停备用
水冷壁
氢损伤
失效
stop standby
water-cooled walls
hydrogen damage
fail
