Relationship to corrosion resistance-thermal fatigue boiler tubes with the heat of the defect structure

The article presents the results of a study on the impact of multiple normalization of the thermal conductivity of carbon steel 20 used in the power system for the manufacture of pipes of heating surfaces. The effect of heat treatment on the emerging nature of corrosive deposits. It has been found that in addition to the phase state of steel 20 on the thermal conductivity value is influenced by structural changes in the steel during heat treatment. With increasing interlamellar distance and cementite platelets thickness thermal conductivity increases. Studies have shown that the thermal conductivity of sample tubes in the delivery state at a temperature close to the operating temperature (300 °C), has a considerable scatter in the data (10 to 20%). Analysis of the samples destroyed showed corrosion rate of thermal fatigue 1.4 times vary depending on the level and type of the thermophysical properties of the scale.