Supplier highlights:This supplier mainly exports to the Democratic Republic of Congo, the UK, and Brazil. They offer full customization, design customization, and sample customization services, and have product certifications.
1. Core Standard Positioning: Clear Specifications for Industrial Applications
ASTM A312 is a standard developed by the American Society for Testing and Materials (ASTM) for seamless and welded austenitic stainless steel pipes. It is specifically designed for pipes used to transport "corrosive fluids, high-temperature, or high-pressure media", with core specifications including:
Clear pipe types: Covers both seamless pipes and welded pipes (e.g., ERW electric resistance welding, SAW submerged arc welding) to meet the needs of different pressure scenarios.
Strict dimensional tolerances: Defines clear deviation ranges for pipe diameter (outer diameter, inner diameter), wall thickness, and length, ensuring compatibility with pipe fittings (valves, flanges).
Mandatory performance testing: Before leaving the factory, pipes must undergo hydrostatic testing (for pressure resistance), non-destructive testing (e.g., eddy current testing, ultrasonic testing to detect internal defects), chemical composition analysis, and mechanical property testing (tensile strength, elongation, etc.) to ensure product consistency and safety.
2. Material Foundation: Inherent Advantages of 300 Series Austenitic Stainless Steel
The 300 series is a core category of austenitic stainless steel (representative grades include 304, 316, 321, 347, etc.), providing key performance support for ASTM A312 pipes:
Excellent corrosion resistance: Mainly relies on the passive film formed by chromium (Cr ≥ 16%) and nickel (Ni ≥ 8%), which can resist common corrosive environments such as air, fresh water, and neutral salt solutions.
Among them, grades 316/316L, with the addition of molybdenum (Mo ≈ 2-3%), have stronger resistance to pitting and crevice corrosion, making them suitable for scenarios involving seawater and chemical solutions (e.g., sulfuric acid, phosphoric acid).
Grades 321/347, with the addition of titanium (Ti) or niobium (Nb), can prevent "intergranular corrosion" (a common defect after high-temperature welding or heat treatment) and are suitable for high-temperature working conditions.
Good mechanical properties: At room temperature, the tensile strength is ≥ 515 MPa and the elongation is ≥ 30%, combining strength and toughness. It can withstand a certain degree of impact and vibration loads, and has excellent processability (can be bent, cut, and welded).
It maintains high strength at high temperatures (e.g., 300-800°C). Grade 304 can be used in heat-resistant scenarios ≤ 870°C, while grades 321/347, due to stabilizing elements, have a heat resistance limit of over 1000°C.
It has no brittleness at low temperatures (e.g., -196°C liquid nitrogen environment), making it suitable for low-temperature fluid transportation (e.g., liquefied natural gas, refrigerants).
