Welded Stainless Steel Pipe

• ​Introduction

Welded stainless steel tube is a tubular product formed by welding stainless steel sheets or strips. Due to its excellent corrosion resistance, high strength, and good high-temperature resistance, it is widely used in chemical, food, medical, construction, and mechanical manufacturing industries. The welding process gives it advantages in production cost and efficiency compared to seamless steel pipes, and strict quality control ensures it meets performance requirements for various applications.

• ​Main Functions

Fluid transportation：Used for conveying media such as water, gas, and oil, e.g., water supply/drainage pipes and gas pipelines.

Structural support：Serves as structural components (e.g., railings, brackets) or support frameworks for mechanical parts.

Corrosion-resistant containers：Applied in chemical and food industries to manufacture reactors, storage tanks, and other corrosion-resistant vessels.

Heat exchange：With good thermal conductivity, it can be used as pipeline material for heat exchangers and radiators.

Decorative purposes：Due to its aesthetic surface and corrosion resistance, it is commonly used in decorative projects.

• ​Tubing Standards

ASTM A312, ASTM A213, ASTM A240，ASTM A269，ASTM A268，ASTM A789 ; EN 10217-7，EN 10312； GB/T 12771，GB/T 12770，GB/T 21833.

• Material & Performance

304/304L，316/316L，410，430，2205，2507 etc. 1.4301/1.4306,1.4401/1.4404,1.4006,1.4016,1.4462,1.4410 etc.

Corrosion Resistance：Excellent performance in corrosive media like acids, alkalis, and salts.

Mechanical Strength：Excellent tensile strength (≥515MPa for 304 stainless steel, ≥655MPa for 2205 duplex steel), as well as good toughness and impact resistance.

Temperature Resistance:Low-temperature environment: Austenitic stainless steels (e.g., 304) maintain toughness at -196℃, suitable for liquefied gas transportation.High-temperature environment: 310S stainless steel can be used long-term at 1200℃.

Surface Properties:Controllable surface finish: Polishing can achieve a mirror effect (Ra≤0.8μm), meeting hygienic requirements for food-grade or medical applications.Passivation film stability: A dense oxide film forms on the surface after passivation, further enhancing corrosion resistance.

Workability & Weldability:Good cold formability: Can be processed by bending, flaring, etc., suitable for complex structure manufacturing.Mature welding processes: Using TIG, HFIW, etc., the weld strength can reach over 90% of the base metal, with corrosion resistance close to that of the substrate.

• ​Manufacturing Process

Raw material preparation：Cut stainless steel coils or sheets into strips according to specifications.

Forming：Roll the strips into tubes using a roll bender to form preliminary round or special-shaped tubes.

Welding：Adopt TIG (Tungsten Inert Gas welding), MIG (Metal Inert Gas welding), or High-Frequency Induction Welding (HFIW) for seam welding, with HFIW being the most efficient.

Weld seam treatment：Remove slag and grind the weld seam, anneal (eliminate stress), or solution treat (austenitic stainless steel).

Dimension finishing：Adjust tube diameter and straightness through sizing and straightening machines to ensure dimensional accuracy.

Surface treatment：Carry out pickling, passivation, polishing, or coating as needed to enhance corrosion resistance and appearance.

Quality inspection：Include hydrostatic testing, non-destructive testing (UT/RT), intergranular corrosion testing, etc., to ensure no leakage and compliance with performance standards.

• Specifications