Austenitic Stainless Steels

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 Grades

Special chemical balance for welding.

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

Cold Heading Grades

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

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

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

Austenitic Steel Grades

Grade
AIM/1
EN #
-
AISI #
201
UNS #
S20100
EN Name
-
BS #
-
Grade
AIMR
EN #
-
AISI #
XM-28
UNS #
S24100
EN Name
-
BS #
-
Grade
AIP
EN #
1.4303
AISI #
305
UNS #
S30500
EN Name
X4CRNI18-12/X5CRNI18-12
BS #
-
Grade
AIP/DE
EN #
-
AISI #
-
UNS #
-
EN Name
-
BS #
347S31/347S20
Grade
AISC
EN #
1.4550/1.4546
AISI #
347/347H
UNS #
834700/834709
EN Name
X6CRNINB18-10/X5CRNINB18-10
BS #
347831/347820
Grade
AISH
EN #
1.4948
AISI #
304H
UNS #
S30409
EN Name
X6CRNI18-10/X6CRNI18-11
BS #
-
Grade
AISH1
EN #
1.4948
AISI #
304H
UNS #
S30409
EN Name
X6CRNI18-10/X6CRNI18-11
BS #
-
Grade
AISH2
EN #
-
AISI #
304H
UNS #
S30409
EN Name
-
BS #
-
Grade
AISL
EN #
1.4301/1.4307/1.4304
AISI #
304/304L
UNS #
S30400/S30403
EN Name
X-5CRNI18·10/X2CRNI18-9
BS #
304S15/304S31
Grade
AISL/DE
EN #
1.4306
AISI #
-
UNS #
-
EN Name
X2CRNI19-11
BS #
304S11
Grade
AISLN
EN #
1.4311
AISI #
304LN
UNS #
S30453
EN Name
X2CRNIN18-10
BS #
-
Grade
AISN
EN #
-
AISI #
304HN
UNS #
S30452
EN Name
-
BS #
-
Grade
AIST
EN #
1.4541
AISI #
321
UNS #
S32100
EN Name
X6CRNITI18-10
BS #
321S31
Grade
AISTH
EN #
1.4878/1.4544
AISI #
321H
UNS #
S32109
EN Name
X8CRNITI18-10
BS #
-
Grade
AMS
EN #
-
AISI #
317
UNS #
S31700
EN Name
-
BS #
-
Grade
AMSL
EN #
-
AISI #
317L
UNS #
S31703
EN Name
-
BS #
-
Grade
AMSL/DE
EN #
1.4438
AISI #
-
UNS #
-
EN Name
X2CRNIM018-15-4
BS #
-
Grade
AMSL/DE2
EN #
1.4439
AISI #
-
UNS #
-
EN Name
X3CRNIM0N17-13-5
BS #
-
Grade
APFIS
EN #
1.4845
AISI #
310/310S
UNS #
S31000/S31008
EN Name
X8CRNI25-21/X12CRNI25-21
BS #
310S31
Grade
APFI/SI
EN #
1.4841
AISI #
314
UNS #
S31400
EN Name
X15CRNISI25-21/X15CRNISI25-20
BS #
314S25
Grade
APFR/SI
EN #
1.4828
AISI #
-
UNS #
-
EN Name
X15CRNISI20-12
BS #
-
Grade
APFR
EN #
1.4833
AISI #
309
UNS #
S30900
EN Name
X12CRNI23-13/X7CRNI23-14
BS #
-
Grade
APFRS
EN #
-
AISI #
309S
UNS #
S30908
EN Name
-
BS #
-
Grade
APM/DE2
EN #
1.4432/1.4436
AISI #
-
UNS #
-
EN Name
X2CRNIM017-12-3/X5CRNIM017-13-3
BS #
316S33/316S14
Grade
APM/UK2
EN #
-
AISI #
-
UNS #
-
EN Name
-
BS #
316S19
Grade
APMC
EN #
-
AISI #
316CB
UNS #
S31640
EN Name
-
BS #
-
Grade
APMC/DE
EN #
1.4580
AISI #
-
UNS #
-
EN Name
X10CRNIMONB18-10
BS #
-
Grade
APMH
EN #
-
AISI #
316H
UNS #
S31609
EN Name
-
BS #
-
Grade
APML
EN #
1.4401/1.4404
AISI #
316/316L
UNS #
S31600/S31603
EN Name
X5CRNIM017-12-2/X2CRNI17-12-2
BS #
316S14
Grade
APMLD2
EN #
1 .4435/1.4437
AISI #
-
UNS #
-
EN Name
X2CRNIM018-14-3/X6CRNIM018-12
BS #
316S13/316S14/316S33
Grade
APMLN
EN #
1.4429
AISI #
-
UNS #
-
EN Name
X2CRNIMON17-13-3
BS #
-
Grade
APMLN/DE
EN #
1.4406
AISI #
316N/316LN
UNS #
S31651/S31653
EN Name
X2CRNIMON17-11-2
BS #
-
Grade
APML/FR
EN #
-
AISI #
-
UNS #
-
EN Name
-
BS #
316S31/316S14
Grade
APMT
EN #
-
AISI #
316TI
UNS #
S31635
EN Name
-
BS #
-
Grade
APMT/DE
EN #
1.4571
AISI #
-
UNS #
-
EN Name
X6CRNIMOTI17-12-2
BS #
-
Grade
APMZ/UK
EN #
1.4427
AISI #
-
UNS #
-
EN Name
X12CRNIM0S18-11
BS #
-
Grade
AU177
EN #
1.4310
AISI #
301
UNS #
S30100
EN Name
X12CRNI17-7
BS #
-
Grade
AU188
EN #
1.4310/1.4300/1.4324
AISI #
302
UNS #
S30200
EN Name
X10CRNI18-8/X12CRNI18-8
BS #
302S31/301S22
Grade
AU188Z
EN #
1.4305
AISI #
303
UNS #
S30300
EN Name
X8CRN1S18-9
BS #
303S31
Grade
AV203
EN #
-
AISI #
XM-1
UNS #
S30300
EN Name
-
BS #
-
Grade
NTR50
EN #
-
AISI #
XM-19
UNS #
S20910
EN Name
-
BS #
-
Grade
NTR60
EN #
-
AISI #
-
UNS #
S21800
EN Name
-
BS #
-
Grade
V2111N
EN #
1.4835
AISI #
F45
UNS #
S30815
EN Name
X9CRNISINCE21-11-2
BS #
-
Grade
V2018MN
EN #
1.4547
AISI #
F44
UNS #
S31254
EN Name
X1CRNIM0CUN20-18-7
BS #
-