Austenitic SS 316 Pipes and Tubes
316 stainless steel pipe and tubes are made with austenitic stainless steel that is similar to the material like 304 and 304L, but with the addition of molybdenum content, it improves the corrosion resistance of the alloy, and also resistance to pitting and crevice corrosion in chloride conditions.
Production Process 316 stainless steel pipe and tube
Stainless steel grade 316 or UNS S31600 are manufactured with the processes like ERW ( Electric Resistance Welded), Seamless and EFW ( Electric Fusion Welding) pipes and tubes having a different form such as round, square, rectangle, etc. having a specific end as Plain, Bevel, and Threaded with a nominal thickness of different schedule ranging from SCH 5 to SCH XXS.
Chemical Composition
| GRADE | Ni | Cr | Si | C | Mn | P | S | Mo | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|
| SS 316 | MIN | 10 | 16 | – | – | – | 0 | 2 | ||
| MAX | 14 | 18 | 0.75 | 0.08 | 2 | 0.045 | 0.03 | 3 | BALANCE | |
| SS 316L | MIN | 10 | 16 | – | – | – | – | 2 | ||
| MAX | 14 | 18 | 0.75 | 0.03 | 2 | 0.045 | 0.03 | 3 | BALANCE | |
| SS 316H | MIN | 10 | 16 | 0 | 0.04 | 0.04 | 2 | |||
| MAX | 14 | 18 | 0.75 | 0.1 | 0.1 | 0.045 | 0.03 | 3 | BALANCE |
316 stainless steel pipe and 316 stainless tubes are manufactured with processes such as cold pilgering process, Extrusion process, tube mill Process, and also Piercing process which needs to be followed by heat treatment and mechanical testing.
Heat Treatment Process
SS 316 pipes and tubes can be undergone common hot working processes. It is recommended to avoid hot working below 927°C. The basic ideal temperature range for hot working is between 1149°C-1260°C.
Annealing is recommended to avoid corrosion resistance post work is recommended, at a temperature range of 1040°C-1175°C. As per requirement, annealing needs to be performed such as full annealing, stress relief annealing, Solution annealing, or even Process annealing.
Properties
The austenitic structure of SS 316 allows its excellent toughness, even down to cryogenic temperatures. 316 stainless steel pipes and tubes have better higher temperature strength with superior corrosion resistance properties.
Physical Properties
| Grade | Density (g/cm3) | Elastic Modulus (GPa) | Mean Co-eff of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat (J/Kg.K) | Electrical Resistivity (nΩ.m) | |||
|---|---|---|---|---|---|---|---|---|---|
| SS 316/L/H | 8 | 193 | 0-100°C | 0-315°C | 0-538°C | at 100°C | at 500°C | 0-100°C | 740 |
| 15.9 | 16.2 | 17.5 | 16.3 | 21.5 | 500 | ||||
| Grade | Tensile Strength | Yield Strength | Elongation | Hardness, MAX | |
|---|---|---|---|---|---|
| [MPA] | [MPA] | (% in 50mm) min | HRB | HB | |
| SS 316 | 515 | 205 | 35 | 95 | 217 |
| 316L | 485 | 170 | 35 | 90 | – |
| 316H | 515 | 205 | 40 | 95 | 217 |
SS 316 pipes and tubes possess good resistance to oxidation in intermittent service temperature up to 870°C and in continuous service to 925°C. However, continuous use at 425°C-860°C is not suggested if corrosion resistance in water is needed. In this instance, 316L is usually recommended as it is resistant to carbide precipitation. Grade 316H is usually recommended where higher strength is required at temperatures above 500°C.
Applications of 316 stainless steel pipes
SS 316 pipes are utilized in different industries like pumps & petrochemicals, cement & construction industries, sugar mills, and others. These 316 stainless tubes are of high quality and cost-effective too for the products like outdoor furniture, luggage, sports bags, and light-duty automotive trim.
Specifications of stainless steel 316 alloy
| GRADE | UNS | OLD BRITISH | EURONORM | SWEDISH | JAPANESE | ||
|---|---|---|---|---|---|---|---|
| BS | EN | NO | NAME | SS | JIS | ||
| SS 316 | S31600 | 316S31 | 58H, 58J | 1.4401 | X5CrNiMo17-12-2 | 2347 | SUS316 |
| SS 316L | S31603 | 316S11 | – | 1.4404 | X2CrNiMo17-12-2 | 2348 | SUS316L |
| SS 316H | S31609 | 316S51 | – | 1.4948 | X6CrNi 18-10 | – | – |
Typical industrial applications of stainless steel 316 pipes and tubes are Brewing, Chemical Industry, Dairy, Food processing, Marine equipment, Petrochemicals, Pharmaceuticals, and more. Typical products manufactured with these Alloy 316 Tubes are Condensers, Heat Exchangers, Filters, Pressure Vessels, Valves, and more.
Specification
Stainless steel 316/L/H Seamless Pipe: ASTM/ASME SA 312/ A 312
Stainless steel 316/L/H Seamless tube: ASTM/ASME SA 213/A 213
Stainless steel 316/L/H ERW Pipe : ASTM/ASME SA 312/ A 312
Stainless steel 316/L/H ERW Tube : ASTM/ASME SA 249/ A 249
