AISI 316LN Forgings: UNS S31653, ASTM A182 F316LN, EN 1.4429

Low-carbon, nitrogen-alloyed austenitic stainless steel. Rolled rings, flanges, shafts, discs, tube sheets, sleeves and bars forged to drawing.

Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China. Data reviewed September 2026.

Designations and equivalents

Chemical composition

Two sets of limits are in circulation for 316LN and they differ in nickel and nitrogen. Purchase orders for forgings should quote the forging specification.

Nitrogen is the controlling difference. A182 F316LN caps nitrogen at 0.16 %, the general grade datasheet allows up to 0.30 %. Where a design relies on the higher nitrogen range for yield strength, state the required range on the order and confirm it against the current edition of the standard.

Mechanical properties

Melting practice and heat treatment

Melting

ASTM A182 allows stainless steels to be melted in an electric furnace with optional separate degassing and refining, in a vacuum furnace, or by either route followed by vacuum or electroslag consumable remelting. Enough discard is taken to keep the product free of injurious piping and undue segregation. Our standard route for 316LN is EAF plus VOD, with ESR available where the drawing or code calls for remelted material.

Heat treatment

A182 also allows an alternative for most austenitic grades including F316LN. If the temperature immediately after hot working has not fallen below the minimum solution annealing temperature, the forging may be individually rapidly quenched direct from the forging heat in line with Table 1. On that route the test blank is forged and quenched under the same conditions as the forgings it represents. This removes one furnace cycle on large rings and is available on request.

Forged products in AISI 316LN

ASTM A182 limits products to 4540 kg (10000 lb). Heavier austenitic forgings are ordered to ASTM A965/A965M, and we quote both. A182 does not permit flanges, elbows, return bends, tees and header tees to be machined directly from bar stock, so these are forged from billet. Cylindrically shaped parts may be machined from forged or rolled solution-annealed austenitic bar without further hot working.

Applications

Testing, inspection and certification

Ultrasonic testing

For austenitic and austenitic-ferritic stainless steel forgings the applicable European standard is EN 10228-4. EN 10228-3 covers ferritic and martensitic steel forgings and states that austenitic and austenitic-ferritic stainless forgings are the subject of EN 10228-4. Ultrasonic testing to ASTM A388/A388M is carried out where an ASTM route is specified.

Mechanical and corrosion testing

Tension testing follows A182 with one test per heat for austenitic grades, and specimens are taken only after all heat treatment is complete. Hardness testing covers a minimum of two pieces per batch or continuous run. Where susceptibility to intergranular attack has to be demonstrated, the practices of ASTM A262 apply. Liquid penetrant examination to ASTM E165 and grain size determination to ASTM E112 are available. Magnetic particle examination does not apply to fully austenitic material, so penetrant testing is used in its place.

Certification

We issue EN 10204 3.1 works certificates, or EN 10204 3.2 certificates witnessed by a third party such as SGS, BV, TUV or Lloyd's. Supplementary requirements under A182, including additional testing and drawing approval showing the rough forged shape and the location of test specimens, apply only when the purchaser calls for them on the order, so list them at enquiry stage.

Questions on AISI 316LN forgings

Other stainless grades we forge

• AISI 316LN
• A182-F316
• A182-F347
• A182-F321
• A182-F309
• A182-F44
• A182-F51
• A182-F53
• A182-F55
• 904L
• Nitronic 50
• Sanicro 28
• All stainless grades

References

ASTM A182/A182M, Standard Specification for Forged or Rolled Alloy and Stainless Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service, Tables 1 and 3 and sections 1.2, 6.2 to 6.5, 7.1 to 7.5 and 9.5. ASTM A965/A965M, Steel Forgings, Austenitic, for Pressure and High Temperature Parts. EN 10228-3:2016 and EN 10228-4:2016, Non-destructive testing of steel forgings. EN 10088 designations for 1.4429 X2CrNiMoN17-13-3. Published grade datasheets for 316LN, UNS S31653. Published literature on Type 316L(N)-IG as an ITER structural material. Standards are revised periodically, so confirm against the current edition at order placement.