Characteristics of 10Cr9Mo1VNbN Alloy Seamless Tubes

Characteristics of 10Cr9Mo1VNbN Alloy Seamless Tubes
The 10Cr9Mo1VNbN alloy seamless tube is a high-performance ferritic/martensitic heat-resistant steel specifically designed for high-temperature and high-pressure environments.
1. Optimized Chemical Composition: Balancing Heat Resistance and Strengthening
Primary Alloying Elements:
Cr (8.0–9.5%): Forms a dense chromium oxide protective layer, significantly enhancing resistance to high-temperature oxidation and corrosion, making it suitable for harsh media containing sulfur or acids.
Mo (0.85–1.05%): Improves high-temperature creep strength through solid-solution strengthening, enhancing material stability during long-term service.
N (0.03–0.07%): Stabilizes the austenitic phase, improving performance stability during welding and heat treatment.
Impurity Control:
P ≤ 0.020%, S ≤ 0.010%, reducing brittleness risks and enhancing material purity.
2. Mechanical Properties: Dual Guarantee of High Temperature and Strength
Room-Temperature Performance:
Tensile strength ≥ 585 MPa, yield strength ≥ 415 MPa.
Elongation after fracture: Longitudinal ≥ 20%, transverse ≥ 18%.
Impact energy: Longitudinal ≥ 40 J, transverse ≥ 27 J.
Hardness: Brinell ≤ 250 HB, Vickers ≤ 265 HV, Rockwell ≤ 25 HRC, balancing strength and ductility.
High-Temperature Performance:
Endurance Strength: Exceeds 100 MPa under 625°C/10⁵h conditions, meeting long-term service requirements for supercritical power units.
Thermal Stability: Maintains excellent strength at 600°C, suitable for critical components like boiler superheaters and reheaters.
3. Processability: Adapting to Complex Manufacturing Demands
Heat Treatment Processes:
Normalizing + Tempering: Normalizing at 1040–1080°C and tempering at 730–780°C eliminate internal stresses and form tempered sorbite, optimizing the balance of strength and toughness.
Intercritical Quenching: Used under special requirements to further enhance low-temperature toughness.
Weldability:
Achieves crack-free welding by controlling carbon equivalent, preheating (200–250°C), and post-weld heat treatment, using matching filler materials like ER90S-B9 special welding wire.
Formability:
Hot Rolling: High production efficiency and low cost.
Cold Drawing: Suitable for high-precision applications but with higher costs.