Heat resistance means that the steel is resistant to scaling at temperatures higher than 500 deg C. Heat resistant steels are meant for use at temperatures higher than 500 deg C since they have got good strength at this temperature and are particularly resistant to short and long term exposure to hot gases.
These steels are solid solution strengthened alloy steels. As these steels are used over a certain broad temperature ranges, these steels are usually strengthened by hard mechanism of heat treatment, solid solution and precipitation. All the heat resistant steels are composed of several alloying elements for the purpose of achieving the desired properties and are used in applications where resistance to increased temperatures is critical.
The level of the heat resistance of the heat resistant steels depends on the environment conditions in which they operate and cannot be characterized by a single testing method.
Such steel is generally used in applications where resistance to increased temperatures are critical. The steel is hard wearing and offers a resistance to large variations in temperature. Industrial applications include furnaces, heat exchanges and incinerators where temperatures can reach in excess of 1100°C.