Elevated temperature mechanical properties for stainless steels specified in BS EN 10028-7

Introduction

Mechanical, (tensile), properties are specified for pressure vessel applications in BS EN 10028-7. These are minimum design values only, and do not represent typical values.
Proof strength values only are specified for a small number of ferritic, martensitic and duplex grades. There is a more extensive range of data for austenitic grades, which specifies 0.2% and 1.0% proof strengths and tensile, (UTS), values.
The values are shown in N/mm² (MPa).

The data given is not intended to replace that shown in individual standards to which reference should always be made.

Ferritic, martensitic and duplex proof strengths

The values assume the steels are in the annealed condition, except for the martensitic grades, which are assumed to be in the quenched and tempered, (QT), condition. The duplex data is reference data only, according to the standard.

Steel number	Minimum 0.2% proof strength (N/mm²) at temperature (°C)
.	100°C	150°C	200°C	250°C	300°C	350°C
Ferritic
1.4003	240	235	230	220	215	.
1.4516	300	270	250	245	225	215
1.4510	195	190	185	175	165	155
1.4521	250	240	230	220	210	205
1.4520	195	180	170	160	155	.
1.4509	230	220	210	205	200	180
Martensitic
1.4313	590	575	560	545	530	515
1.4418	660	640	620	600	580	.
Duplex
1.4362	330	300	280	265	.	.
1.4462	360	335	315	300	.	.
1.4507	450	420	400	380	.	.
1.4410	450	420	400	380	.	.
1.4501	450	420	400	380	.	.

Tensile Strength Values for Duplex (Austenitic Ferritic Stainless Steels) (Preliminary Reference Data)

Steel number	Minimum Tensile Strength (N/mm²) at temperature (°C)
	100	150	200	250
1.4362	540	520	500	490
1.4462	590	570	550	540
1.4507	660	640	640	630
1.4410	680	660	640	630
1.4501	680	660	640	630

Austenitic proof strengths and tensile (UTS) values

The values assume the steels are in the annealed condition. The table shown here only has some of the more popular grades. The standard should consulted for the full range of grades and properties. The ‘0.2%’ is the 0.2% proof strength or R_p0.2 value. Similarly ‘1.0%’ is the 1.0% proof strength or R_p1.0. The ‘UTS’, (ultimate tensile strength), is also known as just ‘tensile strength’, or R_m.

Steel No.	.	Minimum tensile values (N/mm²) at temperature (°C)
.	.	100	150	200	250	300	350	400	450	500	550
1.4307	0.2%	147	132	118	108	100	94	89	85	81	80
	1.0%	181	162	147	137	127	121	116	112	109	108
	UTS	410	380	360	350	340	340	.	.	.	.
1.4301	0.2%	157	142	127	118	110	104	98	95	92	90
	1.0%	191	172	157	145	135	129	125	122	120	120
	UTS	450	420	400	390	380	380	380	370	360	330
1.4311	0.2%	205	175	157	145	136	130	125	121	119	118
	1.0%	240	210	187	175	167	161	156	152	149	147
	UTS	490	460	430	420	410	410	.	.	.	.
1.4541	0.2%	176	167	157	147	136	130	125	121	119	118
	1.0%	208	196	186	177	167	161	156	152	149	147
	UTS	440	410	390	385	375	375	375	370	360	330
1.4550	0.2%	177	167	157	147	136	130	125	121	119	118
	1.0%	211	196	186	177	167	161	156	152	149	147
	UTS	435	400	370	350	340	335	330	320	310	300
1.4404	0.2%	166	152	137	127	118	113	108	103	100	98
	1.0%	199	181	167	157	145	139	135	130	128	127
	UTS	430	410	390	385	380	380	380	.	360	.
1.4406	0.2%	211	185	167	155	145	140	135	131	128	127
	1.0%	246	218	198	183	175	169	164	160	158	157
	UTS	520	490	460	450	440	435	.	.	.	.
1.4401	0.2%	177	162	147	137	127	120	115	112	110	108
	1.0%	211	191	177	167	156	150	144	141	139	137
	UTS	430	410	390	385	380	380	.	.	.	.
1.4571	0.2%	185	177	167	157	145	140	135	131	129	127
	1.0%	218	206	196	186	175	169	164	160	158	157
	UTS	440	410	390	385	375	375	375	370	360	330
1.4539	0.2%	205	190	175	160	145	135	125	115	110	105
	1.0%	235	220	205	190	175	165	155	145	140	135
	UTS	500	480	460	450	440	435	.	.	.	.
1.4547	0.2%	230	205	190	180	170	165	160	153	148	.
	1.0%	270	245	225	212	200	195	190	184	180	.
	UTS	615	587	560	542	525	517	510	502	495	.

Heat treatment guidelines

The prior heat treated condition that the elevated temperature values apply to in the BS EN 10028-7 standard are tabulated below. All ferritic, duplex and austenitic grades can be either air or water cooled from the annealing / solution annealing temperature. Martensitics can be cooled from the ‘quenching’, (austenitising), treatment by either oil, air or water. The standard does not stipulate the cooling method from the second heat treatment, (tempering), temperature for the martensitics.

Grade	Temperature (°C)
Ferritic
1.4003	700-750
1.4516	790-850
1.4510	770-830
1.4521	820-880
1.4520	820-880
1.4509	870-930
Duplex
1.4362	1000 +/- 50
1.4462	1060 +/- 40
1.4507	1080 +/- 40
1.4410	1080 +/- 40
1.4510	1080 +/- 40
Austenitic
1.4307	1000-1100
1.4301	1000-1100
1.4311	1000-1100
1.4541	1000-1100
1.4550	1020-1120
1.4404	1030-1110
1.4406	1030-1110
1.4401	1030-1110
1.4571	1030-1110
1.4539	1060-1140
1.4547	1140-1200
Martensitic
1.4313	950-1050 OQ,AC,WQ + 560-640
1.4418	900-1000 OQ,AC,WQ + 570-650