1) Pearlite or ferrite pearlite heat resistant steel. This kind of steel is usually used after normalizing and high temperature tempering. Its structure belongs to hypoeutectoid steel with ferrite and carbide, and its total alloy element content is generally less than 5%. Because of the low content of anti-oxidation alloy elements in this kind of steel, the working temperature range is 350-620 ℃, which is often used as heat-resistant parts in boilers and gas turbines.

2)马氏体耐热钢。这类钢一般经过淬火一高温回火后使用，这类钢中一部分是在lcr13马氏体不锈钢基础上发展起来的，使用状态是回火马氏体，主要用作气轮机叶片；另一部分以马氏体耐热钢为阀门钢，使用状态是回火索氏体o

2) Martensitic heat resistant steel. This kind of steel is generally used after quenching and high temperature tempering. One part of this kind of steel is developed on the basis of lcr13 martensitic stainless steel, and its service state is tempered martensite, which is mainly used for gas turbine blades; the other part takes martensitic heat-resistant steel as valve steel, and its service state is tempered sorbite o

3)铁素体耐热钢。属于抗氧化钢，系高铬钢加入硅、铝等元素形成的钢。

3) Ferrite heat resistant steel. It belongs to oxidation resistant steel, which is formed by adding silicon, aluminum and other elements into high chromium steel.

4)奥氏体耐热钢。它是在奥氏体不锈钢的基础上发展起来的，可以在600~810℃范围使用，作为抗氧化用钢可工作到1200℃左右。根据其强化方法的不同又分成固溶强化的简单奥氏体耐热钢、用碳化物沉淀硬化的奥氏体钢、用金属问化合物沉淀硬化的奥氏体钢等。奥氏体耐热钢可用作燃气涡轮、航空发动机、工业炉耐热构件等高温材料。

4) Heat resistant austenitic steel. It is developed on the basis of austenitic stainless steel and can be used in the range of 600 ~ 810 ℃. As an anti-oxidation steel, it can work up to 1200 ℃. According to the different strengthening methods, it can be divided into simple austenitic heat-resistant steel with solid solution strengthening, austenitic steel with carbide precipitation hardening, austenitic steel with intermetallic compound precipitation hardening, etc. Austenitic heat-resistant steel can be used as high-temperature materials for gas turbine, aeroengine, industrial furnace and other heat-resistant components.

按性能和用途，模具钢中耐热钢可分成三大类：

According to properties and uses, heat resistant steel can be divided into three categories

1)抗氧化钢。应具有高温抗气体腐蚀(主要是抗氧化)能力。

1) Oxidation resistant steel. It shall have high temperature resistance to gas corrosion (mainly oxidation resistance).

2)热强钢。应具有良好的热稳定性和一定的高温强度。

2) Hot strength steel. It should have good thermal stability and high temperature strength.

3)气阀钢。是动力设备大量使用的钢，它应具有上述西方面的高温性能。

3) Valve steel. It is a kind of steel widely used in power equipment. It should have the high temperature performance mentioned above.

耐热合金按基体元素，一般分为铁基、镍基、销基等耐热合金；按生产工艺，可分为变形耐热合金和铸造耐热合金两大类。变形耐热合金按其高温性能、成型特点，又可分为热稳定变形耐热合金和热强变形耐热合金两种类型。

According to the matrix elements, heat-resistant alloys are generally divided into iron-based, nickel based, pin based and other heat-resistant alloys; according to the production process, they can be divided into deformation heat-resistant alloys and cast heat-resistant alloys. According to their high temperature properties and forming characteristics, wrought heat-resistant alloys can be divided into two types: heat stable wrought heat-resistant alloys and heat strength wrought heat-resistant alloys.