| Duplex stainless steel 2205 | Chloride-bearing and sour service where 300-series steels crack, in welded pipe, tube, sheet and plate (ATI, Alleima) | Extended exposure at 343 to 530 C (475 C embrittlement), welds made with straight chromium filler, and sour service above 232 C (ATI, Alleima) |
| Super duplex stainless steel 2507 | Chloride-bearing seawater, subsea and sour oil and gas service that needs high strength and pitting resistance, in solution-annealed tube, bar and forgings | Prolonged exposure above 250 °C, which lowers impact strength, and hydrogen-induced cracking in cathodically protected subsea steel |
| Lean duplex stainless steel 2304 | Chloride-bearing process piping and heat exchangers, pulp and paper equipment, and strength-limited structures where 304 or 316 would crack or be too weak (Alleima, ATI) | Exposure above about 315 C (600 F), where 475 C embrittlement can follow (ATI); prolonged exposure above 280 C (Alleima); weld metal without an overmatched filler (ATI) |
| Lean duplex stainless steel 2101 (UNS S32101) | Chloride-bearing process equipment where a 300 series grade is too weak or too prone to chloride stress cracking, and nickel cost matters: the grade gives about double the 0.2 % yield of 304 and 316 and no SCC in the boiling CaCl2 U-bend test | Use above about 300 °C: Atlas says held above 300 °C the grade embrittles and only a full solution anneal restores it, and no space-environment data (radiation, outgassing, cryogenic toughness) were found |
| Stainless steel 304 | Corrosion-resistant housings, fasteners and tanks where ordinary steel would rust | Chloride pitting in acidic solutions, and low strength compared with precipitation-hardened steels |
| Stainless steel 301 | Springs, clips and light formed structures where cold-work strength matters more than corrosion resistance | Chloride pitting (critical pitting temperature below 10 C in Outokumpu's test) and carbide precipitation after welding or holding at 427 to 816 C |
| Stainless steel 303 | Heavily machined parts in mild service, such as screws, nuts, bolts, shafts and fittings (Aalco, UPMET) | Chloride and marine service, where Aalco says 303 is not suitable, and welded joints, where Aalco says weldability is poor |
| Stainless steel 316 | Chloride-bearing and marine-grade service where 304 would pit, in annealed sheet, bar and plate | Crevice and pitting attack in seawater condenser tubes, intergranular attack after heating between 500 and 900 C, and modest strength next to precipitation-hardened grades |
| Stainless steel 316L | Welded parts in chloride or marine service, and vacuum hardware that is vacuum-fired | Long holds near 650 C form sigma phase, and seawater service needs a pitting resistance equivalent number greater than 40 (Wikipedia) |
| AISI 302 stainless steel | Springs, washers, screens and wire parts that need an 18-8 stainless steel with more carbon than 304 for strength, while keeping ductility (Elgiloy datasheet) | Strength in the annealed state (about 290 MPa typical yield), and ductility after heavy cold work (elongation falls from 48 % at 0 % cold work to 2.2 % at 80 % cold work, fwmetals table) |
| Stainless steel 304L | Welded parts in corrosive service, where the as-welded condition must resist carbide precipitation | Sea water and chloride service: Carpenter rates 304 and 304L restricted in sea water, and no pitting number for 304L was found |
| Stainless steel 310S | Furnace and heat-treatment parts that run hot in oxidising air up to about 1,050 °C, with good creep strength and oxidation resistance | Sulphur-bearing hot gases, which cut the service limit to 950 °C, and long exposure between 650 and 900 °C, which causes sigma-phase embrittlement and chromium-carbide sensitisation |
| AISI 317L stainless steel | Chloride pitting resistance in process equipment, with a low-carbon grade that limits sensitization in welds | Strength in the annealed state (205 MPa minimum yield) and chloride stress cracking above about 49 °C |
| AISI 321 stainless steel | Welded parts that run hot in oxidising air, from 427 to 850 degC: titanium holds the grade against carbide precipitation in the 800 to 1500 degF range | Strength when annealed (about 241 MPa typical yield) and cold-work strength only, plus exposure of 900 to 1500 degF for long periods, which lowers general corrosion resistance |
| AISI 347 stainless steel | Welded hot-service parts that cannot be re-annealed afterwards: niobium stabilisation resists intergranular attack, and the grade is rated to 800 °C in air | Strength when hot: tensile strength falls from 93.3 ksi at 68 °F to 69.5 ksi at 800 °F (Rolled Alloys), and no vacuum, radiation or atomic-oxygen data were found |
| AISI 347H stainless steel | Welded parts for hot service in air and steam, where creep strength to 1500 degF is needed and niobium stabilisation resists intergranular attack in the as-welded condition | Strength when hot: typical tensile strength falls from 93.3 ksi at 68 degF to 69.5 ksi at 800 degF (Rolled Alloys), and no vacuum, radiation or atomic-oxygen data were found |
| Super-austenitic stainless steel 904L | Sulfuric and phosphoric acid plant, seawater condensers and heat exchangers, and pulp bleaching, in annealed sheet, plate, strip and tube, where 316L or 317L would corrode | Halide-containing acids and boiling magnesium or lithium chloride, where ATI's U-bend test cracked the alloy, and crevices in chloride water (ATI G-48 onset at 18 °C) |
| Nitronic 60 stainless steel | Fasteners, pins, bushings and valve trim that must resist galling and wear while staying austenitic and low in magnetic permeability | General corrosion resistance falls between Types 304 and 316, the alloy is hard to machine, the high-strength bar cannot be hot worked or welded without losing strength, and the sources print no space-environment data |