0102030405
Heat-Resistant Steel
2026-01-26
Heat-resistant steel is a special alloy steel that maintains sufficient strength, good chemical stability (anti-oxidation/corrosion resistance), and microstructural stability at temperatures above 450°C. It is also known as heat-resistant steel or high-temperature non-delamination steel. Widely used in high-temperature industrial fields such as energy, chemical, and aerospace, it serves as a critical material for modern industrial equipment.
1. Core Performance Requirements
Heat-resistant steel must simultaneously meet the following key performance requirements:
| Performance type | Key indicators | Function Description |
| hot strength | creep limit, endurance strength | Resisting Slow Deformation and Fracture under Long-term High Temperature Stress |
| resistance to oxidation | oxidation rate, film stability | Form a dense oxide film to prevent further oxidation of the substrate |
| structural stability | No phase change, no harmful phase precipitation | Maintain the original microstructure and properties under prolonged high-temperature conditions |
| thermal fatigue resistance | cold and hot cycle life | Resisting Thermal Stress Fatigue Crack Caused by Repeated Heating and Cooling |
| process adaptability | casting, forging, and welding properties | Meeting the manufacturing requirements of complex components |
II. Classification System
1. Classification by Performance and Application
| class | main features | applicable temperature | Typical application |
| oxidation resistant steel | Good chemical stability and low loading capacity | 600~1200℃ | furnace floor, heating furnace components, heat exchanger tubes |
| refractory steel | High temperature resistance with antioxidant properties | 450~850℃ | turbine blade, boiler superheater, gas turbine component |
2. Classification by microstructure (industrial mainstream)
| pattern of organization | Properties of alloy | elevated temperature property | Typical grade | application scenarios |
| ferritic type | High chromium (12–30%), low carbon content | Good antioxidant properties, moderate high-temperature strength | 0Cr25Ni5、1Cr17 | Furnace components, heat exchangers, annealing furnace components |
| Austrian type | High-chromium nickel (18-25% Cr, 8-37% Ni), stable austenitic structure | High-temperature strength, good plasticity, and excellent weldability | 1Cr18Ni9Ti、310S(0Cr25Ni20) | Heat-resistant components above 600°C, chemical equipment, and aeroengine ducts |
| Marie type | Chromium (9~13%), can be strengthened by quenching and tempering | High heat intensity and hardness, with moderate oxidation resistance | X10CrMoVNb9-1(T91)、1Cr12Mo | turbine blades, boiler pipes, high temperature fasteners |
| precipitation-hardening type | Strengthening phase formed by aging precipitation containing elements such as Nb, Ti, and Al | extremely high strength below 650°C | GH2132(A-286)、0Cr17Ni7Al | Aerospace engine components and key parts of high-pressure boilers |
| pearl body type | Low-alloy (Cr-Mo-V series) | Stable performance below 580°C with low cost | 15CrMo、12Cr1MoV | power plant boiler, petroleum refining equipment |
III. Role of Key Alloying Elements
Heat-resistant steel achieves performance optimization through precise alloying design, with the primary elements functioning as follows:
| element | key role | Content range |
| chromium （Cr） | Forming a Cr₂O₃ protective film to enhance oxidation resistance and corrosion resistance | 1~30%, increasing with rising temperature |
| nickel （Ni） | Stabilize austenite structure, enhance toughness and high-temperature plasticity | 8~37% (in austenitic steel), with a small amount used in martensitic steel |
| molybdenum （Mo） | improve creep strength and inhibit harmful phase precipitation | 0.5~2.5%, often used in combination with Cr |
| Vanadium (V), Niobium (Nb) | grain refinement, formation of carbides, precipitation strengthening | 0.1~0.5%, significantly improving the durability strength |
| Silicon (Si), Aluminum (Al) | Assist in antioxidant activity and form a composite oxide film | Si≤3%, Al≤5%, for oxidation-resistant steel |
| Tungsten (W), Cobalt (Co) | Improving High Temperature Strength for Ultra-High Temperature Alloys | Addition to high-end heat-resistant steel, with higher costs |
| carbon （C） | Solid solution strengthening and carbide strengthening, with strict control of content | 0.03~0.4%, excessively high levels may reduce toughness and antioxidant capacity |
IV. Typical Brands and Applications
1. Common Heat-Resistant Steel Grades and Their Properties
| the name of a shop | pattern of organization | maximum operation temperature | Main Applications |
| 12Cr1MoV | pearlite | 580℃ | boiler water wall and superheater tube |
| T91/P91 | martensite | 620℃ | supercritical boiler main steam pipe and steam turbine rotor |
| 310S(0Cr25Ni20) | austenite | 1150℃ | heating furnace tube, high-temperature furnace floor, heat treatment equipment |
| GH2132(A-286) | precipitation hardening | 750°C (anti-oxidation) / 650°C (thermal strength) | Turbine Disk and High Pressure Vessel Flange for Aeroengine |
| ZG40Cr25Ni20Si2 | cast austenite | 1050℃ | Cement kiln tuyere guard plate and metallurgical furnace door |
2. Specialized Heat-Resistant Steels for Specific Applications
- Power plant steel: P92 (620℃), SA1017 Gr.92 (650℃), used in ultra-supercritical units to enhance power generation efficiency
- Aerospace: Nickel-based superalloys (e.g., Inconel 718) capable of withstanding extreme temperatures above 1000°C
- Chemical industry: High-silicon heat-resistant steel (with 2-3% Si), resistant to sulfur-containing atmosphere corrosion, used in sulfur recovery units
V. Heat Treatment Process
The heat treatment of heat-resistant steel aims to optimize microstructure and enhance performance, with significant differences among various processing methods:
| type of steel | typical process | process parameters | purpose |
| Austrian type | solution treatment | 1050~1200°C, rapid cooling | Dissolve the carbides to obtain a uniform austenitic structure, thereby enhancing both plasticity and toughness. |
| Marie type | quenching + tempering | Quenching at 950–1050°C, tempering at 730–780°C | Obtain tempered martensite with balanced strength and toughness |
| precipitation-hardening type | solution + aging | Solid solution at 980°C, aging at 700–760°C | The precipitation of γ' phase or carbide significantly enhances the strength. |
| pearl body type | normalizing + tempering | Normalizing at 900–980°C, tempering at 720–760°C | Refine grain size to enhance creep strength and microstructural stability |
VI. Development Trends
- High parameterization: Development of new heat-resistant steel for ultra-supercritical power generation technology above 700℃ to improve energy utilization efficiency
- Lightweight: By optimizing alloys and improving processes, the weight of components is reduced while maintaining performance, thereby lowering energy consumption.
- Corrosion-resistant strengthening: Special corrosion-resistant and heat-resistant steel for harsh working conditions (e.g. high temperature environment with sulfur and chlorine)
- 3D Printing Adaptation: Developing Heat-resistant Steel Powder Materials for Additive Manufacturing to Meet the Demand of Rapid Manufacturing of Complex Components
sum up
Heat-resistant steel is the "backbone" material of high-temperature industry, and its performance directly determines the efficiency, service life and safety of equipment. When selecting heat-resistant steel, it is necessary to consider the working temperature, load conditions, medium environment and cost factors comprehensively, and match the most suitable steel grade and heat treatment process to achieve the best use effect.