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 CH4,and the high-pressure CH4 causes microcracks in the water-cooled wall,causing hydrogen damage,and finally causing the water-cooled wall to fail and burst the pipe.
维普
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