Alloy Seamless Pipes

Published:2025-05-12 | Last Updated: 2025-06-14    Views: 20

I. Alloy seamless pipe related parameters

Outer diameter range: 10mm - 500mm

Wall thickness range: 1mm - 50mm

Length: 3000mm - 12000mm

Carbon content: 0.05% - 0.25

Chromium content: 0.5% - 1.5%

Molybdenum content : 0.1% - 0.5%

Tensile strength: 450MPa - 650MPa

Yield strength: 300MPa - 400MPa

Elongation: 18% - 25% (longitudinal)

Hardness: 120HBW - 200HBW

II. Alloy Seamless Pipe Introduction

Alloy seamless steel pipe is a kind of high-performance pipe widely used in industry. It is made of alloy steel material through precision rolling process, with excellent mechanical properties and corrosion resistance.

III. Alloy seamless steel pipe production process

Hot rolled (extruded seamless steel pipe): round billet→heating→piercing→three-roll tilting, continuous rolling or extruding→detubing→dimensioning (or size reduction)→cooling→billet→straightening→hydraulic test (or flaw detection)→marking→warehousing.

Cold Drawn (Rolled) Seamless Steel Pipe: Round Pipe Billet→Heating→Piercing→Beating→Annealing→Acid Cleaning→Oil Coating (Copper Plating)→Multi-pass Cold Drawing (Cold Rolling)→Billet Pipe→Heat Treatment→Straightening→Hydrostatic Test (Flaw Detecting)→Marking→Stocking .

IV. Alloy pipe quality

12Cr1MoV, P22(10CrMo910)T91, P91, P9, T9, WB36 , Cr5Mo(P5, STFA25, T5,)15CrMo(P11, P12, STFA22), 13CrMo44, Cr5Mo, 15CrMo, 25CrMo, 30CrMo, 40CrMo.

V. Alloy seamless pipe specification table

VI Alloy Steel Seamless Pipes standard comparison and recommendations

i、Snapshot of national standards

ii. Key Differences Comparison

Performance focus:

China/USA: High temperature and pressure (e.g. 600℃ steam pipe) and corrosion resistance (e.g. H₂S environment) are prioritized.

Germany/Japan: Process precision (e.g. OD tolerance ±0.1mm) and surface quality (e.g. Ra≤0.8μm) are prioritized.

Inspection rigor:

U.S.A./Germany: Non-destructive testing (ultrasonic, eddy current) and physical and chemical testing (intergranular corrosion, hardness) are more frequent.

Japan: Processing accuracy (e.g. bending test without cracks) and surface defects (e.g. scratches ≤ 0.05mm) are highly required.

iii、Suggestions for selection

Energy/chemical industry: Priority China GB/T or U.S. ASTM (such as P11/P22 steel), high pressure corrosion resistance.

Nuclear power/aeronautics: choose the U.S. ASME SA-213 or Germany EN 10216-2, creep resistance and purity up to standard.

Precision Machinery: Recommend DIN 2391 from Germany or JIS G3441 from Japan for small tolerance and high surface finish.

International trade: ISO standards can be referred to, but need to verify whether the specific terms meet the requirements of the target country.