Austenitic Stainless Steels

The most common austenitic alloys are iron-chromium-nickel steels and are frequently referred to as 300 series stainless. The best known austenitic Stainless Steel grades are 304/L & 316/L with other well-known grades such as 321 and 310. These grades contain minimum 16% chromium and 6% nickel commonly referred as 18/8 stainless (grade 304). Austenitic grades are generally preferred for their ease of fabrication resulting from a stable metallurgical microstructure at all temperatures combined with good corrosion resistance, mechanical and physical properties.

The addition of molybdenum to a steel containing 18% chromium and 8% nickel improves corrosion resistance and increases significantly the high temperature strength. Grade 316/L is the most common example of this.

Included is the high alloys or “Super Austenitic” with increased chromium and nickel such as 904/L & 310/L containing up to 26% chromium and 22% nickel. Ideal for high temperature use with excellent corrosion resistance to strong acids and chlorides.

Characteristics of Austenitic Stainless Steels:

  • Non-Magnetic.
  • Excellent ductility.
  • Good strength and scaling resistance at high temperatures(310 to 1100 Degrees Celsius)
  • Cold working to increase hardness.
  • Low temperature applications, cryogenic applications.
  • Cannot be hardened by heat treatment.
  • Weldable using all standard procedures and equipment.

Grade and Typical application:

304 – General purpose with good corrosion properties, used for architectural, food processing and domestic industries.

304L – A version of 304 with lower carbon and no requirement for post weld annealing.

310 – A high temperature grade for use in furnace parts.

316 – Used for higher corrosion resistance e.g. marine applications.

316L – A version of 316 with lower carbon and is immune from sensitisation.

321 – Titanium stabilised and suitable for heat resisting applications up to 800°C.

Welding

Special chemical balance for welding.

Grade EN # UNS # EN Name AWS Class.
AISL/EL2 1.4316 S30883 X2CRNI19-9 ER 308L
AISL/EL 1.4316 S30888 X2CRNI19-9 ER 308LSI
APFRS 1.4833 S30908 X12CRNI23-13/X7CRNI23-14 ER 309S
APML/EL 1.4430 S31683 X2CRNIM019-12 ER 316L
APML/EL2 1.4430 S31688 X2CRNIM019-12 ER 316LSI

Cold Heading

Copper is added to improve the austenitic structure and make the steel less prone to cold work hardening.

Grade EN # AISI # UNS # EN Name BS #
AISRU/1 1.4567 - - X3CRMICU18-9-4 394S17
AISRU/2 - 304CU S30430 - 394S17
AISRU 1.4567 306CU S30430 X3CRNICU18-9-4 -
AISRUH 1.4567 304CU S30430 X3CRNICU18-9-4 394S17
AISRUB 1.4560 - - X3CRNICU19-9-2 -
APMRU 1.4578 316CU - X3CRNICUM017-11-3-2 396S17
AU188ZU* 1.4570 - - X6CRNICUS18-9-2 -

* Free machining grade: only for moderate amount of cold heading.

  • Austenitic Stainless Steel
  • Austenitic Stainless Steel
  • Austenitic Stainless Steel
  • Austenitic Stainless Steel
Grade EN # AISI # UNS # EN Name BS #
AIM/1 - 201 S20100 - -
AIMR - XM-28 S24100 - -
AIP 1.4303 305 S30500 X4CRNI18-12/
X5CRNI18-12
-
AIP/DE - - - - 347S31/
347S20
AISC 1.4550/
1.4546
347/
347H
834700/
834709
X6CRNINB18-10/
X5CRNINB18-10
347831/
347820
AISH 1.4948 304H S30409 X6CRNI18-10/
X6CRNI18-11
-
AISH1 1.4948 304H S30409 X6CRNI18-10/
X6CRNI18-11
-
AISH2 - 304H S30409 - -
AISL 1.4301/
1.4307/
1.4304
304/
304L
S30400/
S30403
X-5CRNI18·10/
X2CRNI18-9
304S15/
304S31
AISL/DE 1.4306 - - X2CRNI19-11 304S11
AISLN 1.4311 304LN S30453 X2CRNIN18-10 -
AISN - 304HN S30452 - -
AIST 1.4541 321 S32100 X6CRNITI18-10 321S31
AISTH 1.4878/
1.4544
321H S32109 X8CRNITI18-10 -
AMS - 317 S31700 - -
AMSL - 317L S31703 - -
AMSL/DE 1.4438 - - X2CRNIM018-15-4 -
AMSL/DE2 1.4439 - - X3CRNIM0N17-13-5 -
APFIS 1.4845 310/310S S31000/
S31008
X8CRNI25-21/
X12CRNI25-21
310S31
APFI/SI 1.4841 314 S31400 X15CRNISI25-21/
X15CRNISI25-20
314S25
APFR/SI 1.4828 - - X15CRNISI20-12 -
APFR 1.4833 309 S30900 X12CRNI23-13/
X7CRNI23-14
-
APFRS - 309S S30908 - -
APM/DE2 1.4432/
1.4436
- - X2CRNIM017-12-3/
X5CRNIM017-13-3
316S33/
316S14
APM/UK2 - - - - 316S19
APMC - 316CB S31640 - -
APMC/DE 1.4580 - - X10CRNIMONB18-10 -
APMH - 316H S31609 - -
APML 1.4401/
1.4404
316/316L S31600/
S31603
X5CRNIM017-12-2/
X2CRNI17-12-2
316S14
APMLD2 1 .4435/
1 .4437
- - X2CRNIM018-14-3/
X6CRNIM018-12
316S13/
316S14/
316S33
APMLN 1.4429 - - X2CRNIMON17-13-3 -
APMLN/DE 1.4406 316N/
316LN
S31651/
S31653
X2CRNIMON17-11 -2 -
APML/FR - - - - 316S31/
316S14
APMT - 316TI S31635 - -
APMT/DE 1.4571 - - X6CRNIMOTI17-12-2 -
APMZ/UK 1.4427 - - X12CRNIM0S18-11 -
AU177 1.4310 301 S30100 X12CRNI17-7 -
AU188 1.4310/
1.4300/
1.4324
302 S30200 X10CRNI18-8/
X12CRNI18-8
302S31/
301S22
AU188Z 1.4305 303 S30300 X8CRN1S18-9 303S31
AV203 - XM-1 S30300 - -
NTR50 - XM-19 S20910 - -
NTR60 - - S21800 - -
V2111N 1.4835 F45 S30815 X9CRNISINCE21-11-2 -
V2018MN 1.4547 F44 S31254 X1CRNIM0CUN20-18-7 -