Based on the heat-exchange principles and having the aid of mathematical methods,this paper analyzes the relation between the water scales and the temperature in the boiler superheater-pipe wall,and also analyzes the causes of the crack of the boiler superheater-pipe(20 steel)by using macroscopic analysis methods,metallographic analysis methods and mechanical property test methods.
In order to analyze the reason of cracking occurred in the superheater lutlet header,some experiments were carried out.The result showed that the hydrogen induced cracking (HIC) was the main reason of the failure,and the impingement corrosion accelerated the cracking process.
