ASTM A358 TP316L Stainless Steel Welded Pipe Pickled and Annealed

ASTM A358 specification covers electric fusion welded austenitic chromium nickel stainless steel pipes suitable for industrial projects such as high-temperature and high-pressure corrosive medium transportation projects, food grade sanitary environments, and marine engineering. The tensile strength of ASTM A358/ASME SA358 TP316L material is ≥ 485 MPa, the yield strength is ≥ 170 MPa, the elongation is ≥ 35% (gauge length 50mm), and the hardness HB is ≤ 217 (after solution treatment). It is suitable for dilute sulfuric acid, acetic acid, phosphoric acid, chloride solutions at room temperature and high temperature environments with continuous use temperature ≤ 870 ℃.

ASTM A358 TP316L Stainless Steel Chemical Composition %

ASTM A358 TP316L Stainless Steel Welded Pipe Manufacturing and Testing Requirements

1. Production process

• Welding method: single-sided welding or double-sided welding under inert gas protection
• Post weld treatment: A solution treatment with rapid cooling at 1050-1120 ℃ is required, and the weld seam is pickled and passivated according to ASTM A380 standard

2. Quality Inspection

• Non destructive testing: Conduct 100% radiographic testing (RT) or ultrasonic testing (UT) according to ASTM E164/E213; Perform weld penetration testing (PT) according to ASTM E165

• Pressure test: Conduct a water pressure test of ≥ 1.5 times the design pressure according to the general requirements of ASTM A450

• Surface quality: Ensure no defects such as cracks or lack of fusion, and the inner wall should have a smooth transition

  
  

ASTM A358 TP316L Stainless Steel Compare with ASTM A312 TP316L

ASTM A358 Manufacturing Process and Weld Treatment

The ASTM A358 standard classifies steel pipes into several grades based on welding and post-treatment processes:

1.CLASS 1:

• Process: Automated welding method, no filler metal added.
• Weld Treatment: 100% radiographic inspection (RT) of both inner and outer surfaces of the weld + solution heat treatment of the entire welded pipe.
• Characteristics: Highest quality grade, suitable for the most demanding operating conditions.

2.CLASS 3:

• Process: Automated welding method, with or without filler metal added.
• Weld Treatment: Solution heat treatment of the entire welded pipe.
• Characteristics: The most common grade, suitable for most high-temperature and corrosive environments.

3.CLASS 5:

• Process: Automated welding method, with filler metal added.
• Weld Treatment: No heat treatment required for the weld (As-Welded Condition). Delivery in the as-welded condition is permitted.
• Characteristics: Limited to specific chemical environments where corrosivity is insufficient to cause intergranular corrosion; not recommended for corrosive or high-temperature environments.

4.CLASS 7:

• Process: Similar to Class 1, but without radiographic inspection.
• Weld Treatment: Solution heat treatment of the entire welded pipe.
• Characteristics: A compromise between Class 1 (no radiographic testing) and Class 3 (no filler metal).

5.CLASS 10:

• Process: Double-sided welding process (e.g., TIG), typically with filler metal added.
• Weld Treatment: 100% radiographic inspection of the weld is required, and the entire welded pipe undergoes solution heat treatment.
• Characteristics: Quality comparable to Class 1, but with double-sided welding, resulting in superior weld quality.

ASTM A358 TP316L Stainless Steel Welded Pipe Application

• Chemical industry: ASTM A358 TP316L stainless steel welded pipe is suitable for concentrated sulfuric acid dilution systems due to its strong resistance to sulfuric acid corrosion; Due to its resistance to chloride ion stress corrosion, it is suitable for brine pipelines in chlor alkali engineering.
• Energy Field: ASTM A358 TP316L stainless steel welded pipe can be used for desalination water pipelines in nuclear power plants, provided that low cobalt content control is required. It can also be used for seawater cooling systems on offshore platforms.
• Food and pharmaceutical: ASTM A358 TP316L stainless steel welded pipe with Ra ≤ 0.8 μ m internal surface roughness can be used for CIP/SIP cleaning of pipelines and can also be used as bioreactor culture medium for transportation.