| The working condition of boiler water wall tubes is severe, whose performance is directly influence the safety of the whole power plants, erosion and burst occurred frequently for the furnace tube. And this affected the safe operation of the power plant and its economy seriously. Failure analysis was conducted on the coal powder boiler water wall tube explosion continuously in one power plant, combining with the operation characteristics, working environment and the real situation of power plant boiler. A mechanism of burst was studied by means of macroscopic and microscopic examination, chemical composition analysis. The possibility of far infrared coating by supersonic arc spraying was discussed. The residual life of water wall tube was predicted and economic benefit is evaluated after coating. The main results are as following:(1) The erosion and high temperature corrosion are mainly responsible for the tube burst.(2).The coating of supersonic spraying is a promising method to prevent from erosion and high temperature corrosion.(3) The energy consuming in power plants was decreased and the tube failure is reduced after coating. |
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