1. Material Definition and Standard Specifications
A30128 is a high-strength, precipitation-hardened stainless steel pipe for aviation applications (corresponding to the US designation AMS 5616). Its core characteristics are:
Composition Design:
Chromium-nickel-molybdenum base (Cr 14.0-16.0%, Ni 6.5-7.5%, Mo 0.75-1.25%) + copper-aluminum composite reinforcement (Cu: 1.25-1.75%, Al: 0.75-1.50%);
Low carbon control (C ≤ 0.07%), phosphorus-sulfur limits (P ≤ 0.010%, S ≤ 0.008%);
Implementation Standards: AMS 5616 (Aerospace Material Specification), GB/T 33821 (National Aviation Standard). 2. Core Performance Advantages
Ultra-High Strength:
Tensile strength ≥1310 MPa after aging treatment (three times that of 304 stainless steel);
Fracture toughness KIC ≥90 MPa·√m (balancing strength and crack growth resistance);
Corrosion Resistance: Passes 1500 hours of salt spray testing with no red rust (complies with MIL-STD-810G);
Processing Characteristics: Requires vacuum induction melting + triple heat treatment (solution treatment + cold treatment + aging).
3. Typical Aviation Applications
Critical Load-Bearing Parts:
Aircraft main landing gear outer cylinder;
Engine thrust reverser actuator;
Special Requirements:
Hypersonic vehicle thermal structure support ring;
Spacecraft deployment mechanism hinge.
4. Comparison with Similar Materials
vs. 15-5PH:
Copper and aluminum reinforcement increases strength by 25% and raises temperature resistance to 400°C;
40% higher cost, but fatigue life is three times longer;
vs. A286:
No titanium additions, resulting in better weldability (no strict preheating required).
5. Procurement and Processing Key Points
Key Certifications: NADCAP-certified heat treatment report required;
Processing Warnings:
Electrodischarge machining (EDM) is prohibited (prone to hydrogen embrittlement);
Shot peening is required after machining (residual compressive stress ≥ 700 MPa);
