The classification of heat-resistant steel and heat-resistant alloy

Heat-resistant materials such as heat-resistant steel and heat-resistant alloys are widely used in engines, internal combustion engines, boilers for thermal power generation, turbines, waste incineration equipment, heat treatment furnaces, heaters and other components, and are indispensable materials in many industries. Japan needs to import a large amount of energy from overseas, so for Japan, it is necessary to improve energy efficiency. In order to improve the energy efficiency of various equipment, it is necessary to improve the performance of heat-resistant materials. The improvement of automobile engine performance and the reduction of factory environmental pollutant emissions, to a large extent, depend on the development of heat-resistant materials that can work for a long time at higher temperatures and more severe environments. The development of the industry also depends on the development of heat-resistant materials. Adding or adding elements such as Ni, Co, Mo, W, Ti, and Nb is an effective method to improve the performance of heat-resistant materials such as heat-resistant steels and heat-resistant alloys, and many heat-resistant steels and heat-resistant alloys have been developed using this method . Due to the limitation of the origin of rare elements and the increase in demand for rare elements, the unstable supply of alloy elements in heat-resistant steel and heat-resistant alloys has caused large price fluctuations.

There are many types of heat-resistant steel and heat-resistant alloys. These materials have different environments, different performance requirements, and acceptable prices. For example, the maximum temperature of the intake valve of a car engine is only 500 ° C at most, so the material used is martensitic heat-resistant steel. Ni-based alloys are over-functional materials for automotive engine intake valves and are too expensive. Therefore, heat-resistant materials should be used separately. On the other hand, reducing costs is an eternal issue in manufacturing. Therefore, how to make materials with the same performance from cheaper raw materials is a requirement for heat-resistant materials. Japan developed the provincial Ni and Mo heat-resistant steel during World War II. Since then, Japan has developed the provincial resource-based heat-resistant material for more than 60 years.