Application Environments of Heat-Resistant Steel Castings

The earliest materials used in boilers and heating furnaces were low-carbon steel, typically operating at temperatures around 200℃ and pressures of only 0.8MPa. Even with the use of low-carbon steel for boilers, such as 20g, the operating temperature did not exceed 450℃ and the working pressure did not exceed 6MPa. With the continuous increase in operating temperatures and pressures of various power devices, modern heat-resistant steels now operate at temperatures as high as 700℃, and the operating environments have become more complex and demanding. The operating temperature range of heat-resistant steel is 200–1300℃, and the working pressure ranges from several MPa to tens of MPa. The working environments have evolved from simple oxidizing atmospheres to more complex environments such as sulfiding atmospheres, mixed atmospheres, and molten salts and liquid metals.