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China Suppliers of 22Cr12NiWMoV High Temperature Alloy - Martensitic Precipitation-Hardening Stainless Steel Factory
Description
22Cr12NiWMoV is a typical martensitic precipitation-hardening stainless steel, also classified as a high-temperature alloy. By incorporating various strengthening elements (such as W, Mo, V, and Nb) into a low-carbon martensitic matrix and undergoing appropriate heat treatment, it achieves excellent high strength, good toughness, fatigue resistance, and a certain degree of corrosion and oxidation resistance at high temperatures (typically below 600°C).
DZ 2.11.31-2021, an industry standard issued by the Aviation Industry Corporation of China (AVIC), is known as the "Specification for Hot-Rolled and Forged Bars for Aeroengines." This standard strictly stipulates the technical requirements for alloy bars used in the manufacture of key hot-end components of aircraft engines (such as turbine disks, compressor disks, blades, and shafts), covering chemical composition, mechanical properties, microstructure, and ultrasonic testing.
The 22Cr12NiWMoV material based on the DZ 2.11.31-2021 standard represents that its quality fully meets the stringent requirements of the aviation engine field for high performance, high reliability and high consistency.
Core Features and Applications
Key Features
- Combination of high strength and good toughness: Strengthening is achieved through martensitic transformation and subsequent aging treatment to precipitate intermetallic compounds (such as Laves phase) while maintaining sufficient toughness.
- Excellent thermal strength: It can still maintain high strength, creep resistance and stress relaxation resistance in the temperature range of 550℃ ~ 620℃.
- Good corrosion and oxidation resistance: Contains about 12% chromium, making it more stable than ordinary alloy steel in high temperature environments.
- Excellent processing performance: Good hot working formability (forging, rolling) and cutting performance.
Typical Applications (Aeroengines)
- Turbine rotor blades: Especially the working blades of the medium and low pressure turbines in the last few stages.
- Compressor rotor blades and disks: Used for the latter stages of disks and blades with higher operating temperatures.
- Ring parts and fasteners: Such as high-temperature bolts, springs and other key connecting parts.
- Other fields: Widely used in high-end equipment manufacturing such as gas turbines and nuclear energy equipment.
Key Technical Requirements of DZ 2.11.31-2021 Standard
This standard sets comprehensive requirements for 22Cr12NiWMoV bars to ensure their aviation-grade quality.
1) Chemical Composition (Melting Analysis)
| Element | Specified Range (wt %) | Effect |
|---|---|---|
| C | 0.20 ~ 0.25 | Ensure the strength of the martensite matrix and form carbides |
| Cr | 11.0 ~ 13.0 | Provides resistance to oxidation and corrosion |
| Ni | 0.50 ~ 1.00 | Stabilize austenite, improve toughness and hardenability |
| W | 1.50 ~ 2.00 | Solid solution strengthening, improving thermal strength and recrystallization temperature |
| Mo | 0.90 ~ 1.25 | Solid solution strengthening, suppressing temper brittleness and improving strength |
| V | 0.20 ~ 0.40 | Forming fine VC, V4C3 carbides, precipitation strengthening |
| Nb | 0.20 ~ 0.40 | Form stable NbC, refine grains, and improve strength and plasticity |
| S, P | ≤ 0.015 | Strictly control harmful elements and improve purity |
Note: The standard has extremely strict control over the content range of alloying elements to ensure the stability and reproducibility of material properties.
2) Mechanical Properties
The room temperature mechanical properties of bars after a specific heat treatment system (usually quenching + tempering) must meet the following indicators:
| Performance Indicators | Numerical Range | Test Conditions |
|---|---|---|
| Tensile strength (Rm) | ≥ 930 MPa | Room temperature |
| Specified non-proportional elongation strength (Rp0.2) | ≥ 780 MPa | Room temperature |
| Elongation after break (A) | ≥ 15% | Room temperature |
| Sectional reduction (Z) | ≥ 55% | Room temperature |
| Impact energy (KU₂) | ≥ 63 J | Room temperature |
High Temperature Durability (e.g. at 550°C / 530MPa):
Durable life: ≥ 100 hours (specific test conditions and requirements are strictly specified in the standard).
3) Metallurgical Quality and Non-Destructive Testing
This is the core that distinguishes aviation standards from ordinary industrial standards:
- Macrostructure: The tower-shaped hairline inspection and acid immersion macrostructure shall not have defects such as shrinkage cavities, bubbles, cracks, inclusions, or white spots visible to the naked eye.
- High magnification structure: The grain size is usually required to be no less than level 4, with a uniform structure, no overburning, and controlled delta ferrite content.
- Non-metallic inclusions: Extremely strict restrictions on the levels of A, B, C, and D inclusions (usually requiring the fineness to be ≤ level 1.5, or higher).
- Ultrasonic flaw detection: 100% ultrasonic testing is carried out in accordance with standard methods. Strict acceptance criteria are set for the size of equivalent flat-bottom hole defects (e.g. Φ1.2mm or smaller).
Heat Treatment System
DZ standards recommend or specify heat treatment systems to ensure that the material achieves the expected performance. The typical aviation heat treatment system for 22Cr12NiWMoV is:
Summary
22Cr12NiWMoV is a technologically mature, high-performance martensitic heat-resistant steel. When produced and controlled according to the DZ 2.11.31-2021 standard, its material properties, metallurgical quality, and consistency reach top-tier levels for aircraft engine applications.
For engineers who choose this material, specifying compliance with the DZ 2.11.31-2021 standard means obtaining highly reliable material performance assurance in high-temperature and high-stress environments.