Study on Tensile Creep Behavior of 12Cr1MoV Alloy Steel under High-Temperature Alkali Metal Salt Environment for Solar Thermal Power Generation

Abstract

The heat exchange tubes of solar thermal power generation work in molten salt environment with periodic temperature change. In order to reveal the tensile creep behavior of 12Cr1MoV pipeline steel under high-temperature alkali metal salt environment, the tensile creep behavior of 12Cr1MoV alloy under different applied load and reaction temperature in high-temperature alkali metal chloride salt environment was studied. The results show that the deformation of 12Cr1MoV alloy in 600°C, NaCl-35%KCl mixed salt environment is mainly controlled by diffusion creep; with the increase of stress, the creep life of 12Cr1MoV alloy decreases. The creep fracture mechanism of 12Cr1MoV alloy in 600°C, NaCl-35%KCl mixed salt environment is intergranular ductile fracture; the increase of temperature will enhance the activation and oxidation of the chlorine atoms, thereby accelerating the corrosion of the base metal and increasing the spheroidization speed of the pearlite matrix, and the creep deformation rate of the alloy increases with increasing temperature.