Analysis on the fitness of heat-resistant steel as casing material in corrosive environment at high temperature

Abstract

This study investigates the performance of heat-resistant steel in a corrosive environment at high temperatures, focusing on mechanical characteristics and corrosion behavior. Firstly, the performance of heat-resistant steel at high temperature was verified using mechanical property measurement, fracture failure analysis, and high-temperature creep test. The results indicate that the tensile strength and yield strength of heat-resistant steel at 350 °C are separately for 930 MPa and 776 MPa. The specimen has good creep resistance and no creep between 100 ∼ 350 °C. After establishing that the high-temperature performance of heat-resistant steel complies with the specifications, the weight loss and stress corrosion tests were carried out in a corrosive environment at high temperatures. The results reveal that the corrosion rate is 0.9504 mm/a at 350 °C, and the corrosion products mainly consist of FeSx, FeCO3 and Fe3O4. The four-point bending test specimen did not crack at all test temperatures. The results show that heat-resistant steel has excellent properties and can be used as the casing material of a complex deep well at high temperatures.