Steels resistant to high working temperatures are capable of working steels at temperatures above 300°C.
If we compare this type of steel with conventional steels, it can be seen that as the temperature increases, its mechanical resistance remains at a similar value compared to the drastic drop that occurs in conventional steels such as S275, which are not designed to withstand high temperatures. temperatures.
Heat-resistant steels are designed to have good resistance to both short-term and long-term elevated temperatures and to exposure to hot gases and combustion products at temperatures above 500º. These steels are usually suitably alloyed to enhance their main characteristic.
Heat resistant steel is strengthened by alloys and heat treatments. The main components added to steel is chromium and molybdenum.
Chromium is present in all types of heat resistant steel and offers resistance to oxidation, resistance to high temperatures and resistance to carburizing.
Molybdenum manages to improve the hardness and toughness of steel by dissolving ferrite and forming carbides.
Materials that are present in heat resistant steels contain approximately 0.5% to 9% Cr and 0.5% to 1.0% Mo, which combined impart better creep resistance to alloy steels. and resistance to corrosion at elevated temperatures. Cr-Mo alloy steels are widely used in petroleum refineries, chemical industries and fossil fuel-fired power plants for pipelines, heat exchangers, superheater tubes, valves, bolts, gas turbine parts, steam turbine rotors. and pressure vessels.