Stainless steel

The term "Stainless steel" is used for the following as a collective name for austenitic stainless steels. The chrom content (Cr) of austenitic stainless steels lies about 17 up to 20%, whereas the nickel portion (Ni) is at least 8%. Thereby the stability against corrosion is achieved. Through the addition of further alloy components, as molybdän (Mo), titan (Ti) etc., can this stability be improved.

Sulphur (S) improves the cutting of the material but impaires the welding quality. Nitrogen (N) can improve the mechanical properties.

The austenitic stainless steels are well formable, well weldable and very corrosion resistant. Moreover, they have good toughness properties and are also usable in low temperatures up to -271 °C.

The austenitic stainless steels are not magnetic when annealed. During shapening strain hardening can occur. Thereby it can come to martensite development and low magnetisability. Through annealing the strain hardening and the magnetism can be undone.

Chemical composition of austenitic stainless steels

Mat. No.	Group	Abbreviation	C % max	Si % max	Mn % max	P % max	S % max	Cr %	Mo %	Ni %	Others % max
1.4301	A2	X 5 CrNi 18.10	0,07	1,0	2,0	0,045	0,030	17,0-19,0	-	8,5-10,5	N 0,11
1.4305	A2	X 10 CrNiS 18.9	0,12	1,0	2,0	0,065	0,350	17,0-19,0	-	8,0-10,0	N 0,11, Cu 1
1.4306	A2	X 2 CrNi 19.11	0,03	1,0	2,0	0,045	0,030	18,0-20,0	-	10,0-12,5	N 0,11
1.4307	A2	X 2 CrNi 18.9	0,03	1,0	2,0	0,045	0,030	17,5-20,0	-	8,0-10,0	N 0,11
1.4401	A4	X 5 CrNiMo 17.12.2	0,07	1,0	2,0	0,045	0,030	16,5-18,5	2,0-2,5	10,5-13,5	N 0,11
1.4404	A4	X 2 CrNiMo 17.13.2	0,03	1,0	2,0	0,045	0,030	16,5-18,5	2,0-2,5	11,0-14,0	N 0,11
1.4435	A4	X 2 CrNiMo 18.14.3	0,03	1,0	2,0	0,045	0,025	17,0-18,5	2,5-3,0	12,5-15,0	N 0,11
1.4539	A4	X 2 NiCrMoCuN 25.20.5	0,03	1,0	2,0	0,030	0,020	19,0-21,0	4,0-5,0	24,0-26,0	N 0,15; Cu 2
1.4541	A2	X 6 CrNiTi 18.10	0,08	1,0	2,0	0,045	0,030	17,0-19,0	-	9,0-12,0	Ti 5x%C, 0,8
1.4571	A4	X 6 CrNiMoTi 17.12.2	0,08	1,0	2,0	0,045	0,030	16,5-18,5	2,0-2,5	10,5-13,5	Ti 5x%C, 0,8

Physical qualities of austenitic stainless steels

Mat. No.	Spec. gravity g/mm³	Elastic modulus kg/mm² (20 °C)	Tensile strength N/mm²	Heat expansion 10-6 K-1 (20-100 °C)	Heat conductivity W/mK (20 °C)	Spec. heat kJ/kgK (20 °C)	Electric resistance Ω mm²/m (20 °C)
1.4301	7,90	200	500-750	16,5	15	500	0,73
1.4305	7,90	200	500-700	16,5	15	500	0,73
1.4306	7,90	200	450-700	16,5	15	500	0,73
1.4307	7,90	200	450-700	16,5	15	500	0,73
1.4401	7,98	200	550-700	16,5	15	500	0,75
1.4404	7,90	200	450-700	16,5	15	500	0,75
1.4435	7,90	200	500-700	16,5	15	500	0,75
1.4539	7,90	200	500-700	16,5	15	500	0,73
1.4541	7,90	200	540-740	16,5	15	500	0,73
1.4571	7,98	200	540-690	16,5	15	500	0,75

International material comparison

Germany W.-Nr.	USA AISI	UNS	Schweden SS	Frankreich AFNOR	England BS	Italien UNI	Spanien UNE	Japan JIS	Russland GOST
1.4301	304	S 30400	2332	Z 6 CN 18.09	304 S 15	X 5 CrNi 18.10	F.3504-X 5 CrNi 18.10	SUS 304	08Ch18N10
1.4305	303	S 30300	2346	Z 10 CNF 18.09	303 S 31	–	–	–	–
1.4306	304L	S 30403	2352	Z 2 CN 18.10	304 S 11	X 3 CrNi 18.11	F.3503-X 2 CrNi 18.10	SUS 304L	03Ch18N11
1.4307	304L	–	–	–	–	–	–	–	–
1.4401	316	S 31600	2347	Z 6 CND 17.11	316 S 31	X 5 CrNiMo 17.12	F.3534-X 5 CrNiMo 17.12.2	SUS 316	–
1.4404	316L	S 31603	2348	Z 2 CND 17.12	316 S 11	X 2 CrNiMo 17.12	F.3533-X 2 CrNiMo 17.13.2	SUS 316L	–
1.4435	316L	S 31603	2353	Z 2 CND 17.13	316 S 11	X 2 CrNiMo 17.13	F.3533-X 2 CrNiMo 17.13.2	SUS 316L	03Ch17N14M3
1.4539	904L	N 08904	2562	Z 1 NCDU 25.20	–	–	–	–	–
1.4541	321	S 32100	2337	Z 6 CNT 18.10	321 S 31	X 6 CrNiTi 18.11	F.3523-X 6 CrNiTi 18.10	SUS 321	06Ch18N10T
1.4571	316Ti	S 31635	2350	Z 6 CNDT 17.12	320 S 31	X 6 CrNiMoTi 17.12	F.3535-X 6 CrNiMoTi 17.12.2	SUS 316Ti	10Ch17N13M2T

AISI = American Iron and Steel Institute, UNS = Unified Numbering System, SS = Swedish Standard, AFNOR = Association Française de Normalisation, BS = British Standard