How much do you know about 304 stainless steel pipes

There are many classifications of 304 stainless steel pipes. Firstly, there are seamless steel pipes and straight seam welded steel pipes. Secondly, the most basic classification is structural 304 stainless steel pipes and industrial fluid transportation 304 stainless steel pipes. There is also the classification based on national standards, Japanese standards, American standards, etc. 304 stainless steel pipes are categorized according to national standards GB/T14976-2012 (Seamless Stainless Steel Pipes for Fluid Transportation), GB/T14975-2012 (Seamless Stainless Steel Pipes for Structural Use), GB/T13296-91 (Seamless Stainless Steel Pipes for Boilers and Heat Exchangers), decorative welded stainless steel pipes (GB/T 18705-2002), and stainless steel welded pipes for building decoration (JG/T 3030-1995). All products undergo rigorous testing and meet the technical specifications of national standards.

The chemical composition of 304 stainless steel pipes (%): Carbon: ≤0.08%, Silicon: ≤1.00%, Manganese: ≤2.00%. Phosphorus: ≤0.045, Sulfur: ≤0.030, Chromium: 18.00~20.00, Nickel: 8.00~10.5

Mechanical Properties of 304 Stainless Steel Pipe:

Tensile Strength of 304 Stainless Steel Pipe: σb (MPa) ≥515-1035

Yield Strength of 304 Stainless Steel Pipe: σ0.2 (MPa) ≥205

Elongation of 304 Stainless Steel Pipe: δ5 (%) ≥40

Hardness of 304 Stainless Steel Pipe: ≤201HBW; ≤92HRB; ≤ 210HV

Density of 304 stainless steel pipe (20℃, g/cm3): 7.93

Melting point of 304 stainless steel pipe (℃): 1398~1454

Specific heat capacity of 304 stainless steel pipe (0~100℃, KJ·kg-1K-1): 0.50

Thermal conductivity of 304 stainless steel pipe (W·m-1·K-1): (100℃) 16.3, (500℃) 21.5

Coefficient of 304 stainless steel pipe (10-6·K-1) : (0~100℃) 17.2, (0~500℃) 18.4

Resistivity of 304 stainless steel pipe (20℃, 10-6Ω·m²/m): 0.73

Longitudinal modulus of 304 stainless steel pipe (20℃, KN/mm²): 193

Production process of 304 stainless steel pipe: Round billet → Heating → Piercing → Three-roll skew rolling, continuous rolling or extrusion → Tube removal → Sizing (or reduction) → Cooling → Billet tube → Straightening → Hydrostatic test (or flaw detection) → Marking → Warehousing.

Production process of cold-drawn (rolled) 304 seamless stainless steel pipe: Round billet → Heating → Piercing → Heading → Annealing → Pickling → Oiling (copper plating) → Multi-pass cold drawing (cold rolling) → Billet tube → Heat treatment → Straightening → Hydrostatic test (flaw detection) → Marking → Warehousing.

304 stainless steel pipe is one of the most widely used chromium-nickel stainless steels. As a versatile steel, it possesses good corrosion resistance, heat resistance, low-temperature strength, and mechanical properties; it has good hot workability, such as stamping and bending, and does not exhibit heat treatment hardening (operating temperature -196℃～800℃). It is corrosion-resistant in the atmosphere; however, in industrial atmospheres or heavily polluted areas, timely cleaning is necessary to prevent corrosion. It is suitable for food processing, storage, and transportation. It has good processing performance and weldability. Applications include plate heat exchangers, corrugated pipes, household goods (Class I and II tableware, cabinets, indoor piping, water heaters, boilers, bathtubs), automotive parts (windshield wipers, mufflers, molded parts), medical equipment, building materials, chemical industry, food industry, agriculture, and shipbuilding components.