Application description

Widely used in high-temperature and high-pressure services such as boiler tubes, superheaters, heat exchangers, refinery piping, petrochemical plants, power generation (fossil and nuclear), and steam lines. Also suitable for pressure vessels, chemical processing, and gas cylinders. Chromium-molybdenum alloys provide excellent creep resistance and oxidation protection up to 600°C.

Production description

Alloy steel billet or coil is heated, then rolled (seamless) or formed and welded (welded). The pipe undergoes heat treatment (normalizing, quenching & tempering) to achieve the required microstructure and mechanical properties. It is then straightened, cut to length, 100% NDT inspected (UT, hydrostatic), and end-finished (beveled or plain). Optional pickling or coating applied.

Shipping Packaging

For export, alloy steel pipes are fitted with plastic end caps, bundled with steel straps, packed on ISPM-15 pallets or steel skids, and secured with edge protectors. For pickled & oiled surfaces, additional VCI paper and moisture-proof wrapping applied. Labels include grade, dimensions, heat treatment condition, and heat number.

Why Choose Us?

1.Factory Strength: Direct manufacturer with seamless and welded pipe production lines, heat treatment furnaces (normalizing, Q&T), and in-house NDT facilities, producing alloy steel pipes to ASTM, EN, and GB standards.

2.Quality Assurance: Strict control of chemical composition, mechanical properties (tensile, yield, elongation, hardness), creep resistance, and NDT (100% UT, hydrostatic); compliant with ASTM A335/A213/A519, EN 10216-2, GB/T 8162.

3.Certifications & Reports: Mill test certificates (MTC) with each shipment; third-party inspections (SGS, BV) and test reports (tensile, hardness, impact, creep) available upon request.

4.Customization & Service: Wide grade range (15CrMo, 12Cr1MoV, T91, P91, P22, 4130, etc.), diameters 6–1200mm, wall 2–60mm, custom lengths, heat treatment conditions, bevelled ends, and fast lead times.

5.Export Packaging: Plastic end caps + VCI paper (for pickled surfaces) + moisture-proof wrapping + ISPM-15 pallets/steel skids + steel strapping + edge protectors + clear labeling for safe sea freight.

FAQ

1.How to store alloy steel pipes to prevent corrosion and damage?

Store in dry, covered area on wooden sleepers, keep end caps on. For pickled and oiled pipes, avoid moisture. Chromium-molybdenum alloys are less prone to rust but still require protection. Minor surface rust can be removed by wire brushing before installation.

2.What is the difference between P11 and P22 alloy steel pipe?

P11 (1.25Cr-0.5Mo) is used for service up to 550°C, common in boiler headers and steam lines. P22 (2.25Cr-1Mo) offers higher creep resistance and oxidation resistance up to 600°C, used in superheaters, refineries, and high-temperature petrochemical service. Choose P22 for more severe temperature conditions.

3.Can alloy steel pipes be welded without preheat?

Preheating is generally required for chrome-molybdenum grades to prevent cracking in the heat-affected zone. For P11, preheat to 150-200°C; for P22, 200-250°C; for P91, 200-300°C. Use low-hydrogen electrodes (e.g., E9018-B3 for P22) and follow PWHT recommendations. We provide welding procedure specifications upon request.