Electric power industry is the basic industry of national economy and the material basis of realizing modernization

Corrosion and erosion resistance of "four pipes" of boiler in power plant

     Coal-fired power plants, the high temperature and high pressure, boiler water wall tube, superheater tubes, reheater tube, the provincial gas pipe (quads) often thinned due to high temperature corrosion and wear, replace pipe is not only time-consuming, expensive if cause "four tube" leakage blowout accident, temporary repair and overhaul of the workload will increase power plant, bring a great economic loss power plant.It has become an urgent technical problem to be solved in the safe operation of thermal power plants.
 

     From the early 1980s, a material was designed abroad to provide long-term protection for boiler pipes (no repairs within 3-5 years).The objective is to develop a coating that does not flake, has a loss rate of less than 10% of the unprotected steel pipe, and is more cost-effective than replacing boiler tubes.After years of research, and through experimental tests and field application assessment, has obtained gratifying results, coating thickness annual average loss rate best up to 0.025mm, working life up to 5~10 years, greatly improve the "four pipe" working life
 

     With the continuous development of power industry and the popularity of thermal spraying technology, NiAl coating is used as the bonding base layer, NiCrAl coating is used as the working layer, and high temperature coating is used to seal the holes on the surface. The coating system has achieved good protection effect in the industrial test in the factory, with an annual wear rate of 0.04mm.Working life up to two overhaul period (6 years) to the power plant to bring significant economic benefits.