Elevated temperature physical properties of stainless steels

Introduction

BS EN 10088-1 gives a limited amount of data for specification purposes. Above ambient temperatures this is limited to modulus of elasiticity (Youngs modulus) and coefficients of thermal expansion. The maximum temperature for which there is data is 500 degC.

There is more detailed 'typical' data in the INCO publication 'Austenitic chromium-nickel stainless steels-engineering properties at elevated temperatures'.This including tensile and shear modulus data, Poisson's ratio, density, thermal expansion, conductivity, specific heat and electrical resistivity. A selection from this data is tabulated in this article for the common austenitic grades only. Some of the data shown in this article is interpolated from graphs in the original publication.

BSSA does not accept any responsibility for the accuracy of the data shown in this article.

Elevated temperature modulii of elasticity and coefficients of expansion for stainless steels specified in BS EN 10088-1

The table below is based on the reference data presented in BS EN 10088-1. Only a sample of the information is shown for the most commonly used stainless steel types. These are grouped using 'AISI' steel types. The separate table indicates some of the grades that have been grouped together.

Steel Types (AISI)	Modulus of elasticity (kN/mm2), at:						Mean coefficient of thermal expansion (10-6 x K-1) between 20C and :
Temp.	20C	100C	200C	300C	400C	500C	100C	200C	300C	400C	500C
Ferritic stainless steels
410S	220	215	210	205	195	-	10.5	11.0	11.5	12.0	12.0
430	220	215	210	205	195	-	10.0	10.0	10.5	10.5	11.0
444	220	215	210	205	195	-	10.4	10.8	11.2	11.6	11.9
Martensitic and precipitation hardening stainless steels
410	215	212	205	200	190	-	10.5	11.0	11.5	12.0	-
440	215	212	205	200	190	-	10.4	10.8	11.2	11.6	-
630	200	195	185	175	170	-	10.9	-	11.1	-	-
Austenitic stainless steels
304	200	194	186	179	172	165	16.0	16.5	17.0	17.5	18.0
316	200	194	186	179	172	165	16.0	16.5	17.0	17.5	18.0
'6%Mo'	195	190	182	174	166	158	16.5	17.0	17.5	18.0	18.0
Duplex stainless steels
'2205'	200	194	186	180	-	-	13.0	13.5	14.0	-	-

Some of the EN grades covered by the 'steel types' are shown in the following table.

AISI	EN Grades Covered
410S	1.4000
430	1.4016
444	1.4521
410	1.4006 (410), 1.4005 (416), 1.4021 (420)
440	1.4112 (440B), 1.4122, 1.4125 (440C)
630	1.4542 (17/4 PH)
304	1.4301(304), 1.4305 (303), 1.4306 (304L), 1.4307 (304L), 1.4541 (321), 1.4550 (347)
316	1.4401 (316), 1.4404 (316L),
'2205'	1.4462 (2205)
'6%Mo'	1.4547 (254SMO)

Elevated temperature physical properties for austenitic stainless steels (INCO Publication 2980 Data)

The tables are based on graphs and tables shown in the INCO publication 'Austenitic chromium-nickel stainless steels-engineering properties at elevated temperatures'. This data is based on measured values, usually reported in 'fps' units with temperatures in degrees Fahrenheit. Here, these have been taken as the nearest values and so are for guidance only, not for specification purposes. Only part of the available data is shown here. The full publication (INCO 2980) is available from the Nickel Institute website

 

Modulus of Elasticity (E) and Rigidity(Shear) (G) (E/G)

Temp C	304	316	310
24	19.9/8.0	19.9/7.9	20.3/7.9
90	19.6/7.8	19.8/7.7	19.8/7.7
150	19.1/7.6	19.3/7.5	19.3/7.5
200	18.7/7.4	18.9/7.2	18.8/7.2
260	18.3/7.2	18.5/7.0	18.4/7.0
320	18.0/7.0	18.0/6.8	17.9/6.8
370	17.4/6.8	17.5/6.6	17.5/6.6
430	16.9/6.7	16.7/6.4	17.0/6.4
480	16.3/6.5	16.5/6.2	16.6/6.2
540	15.8/6.3	16.0/6.0	16.2/6.0
590	15.3/6.0	15.6/5.8	15.8/5.8
650	14.8/5.8	15.1/5.7	15.3/5.6
700	14.3/5.6	14.6/5.6	14.9/5.3
760	13.6/5.4	14.0/5.4	14.4/5.0
820	12.7/5.2	13.4/5.3	13.4/4.9
870	-	-	13.5/4.6

Units are kgf/mm² x 10³ (multiply by 9.807 to convert to N/mm²)

Poisson's Ratio

Temp C	304	316	310
150	0.28	0.26	0.32
260	0.30	0.29	0.31
370	0.32	0.34	0.31
480	0.28	0.30	0.32
590	0.29	0.32	0.34
700	0.28	0.31	0.34
820	0.25	0.24	0.29

Poisson's ratio does not have any units.

Density

Temp C	301	316
20	7910	7950
90	7880	7920
200	7840	7880
320	7790	7830
430	7740	7790
540	7690	7740
650	7640	7690
760	7590	7640
870	7540	7590

Units have been converted in this table into Kg/m³

Thermal Expansion

These are 'average' values between 20 degC and the temperature shown, not 'instantaneous' values ie specific values for the temperature shown. The values are taken from the graph, Fig31, and so are subject to some interpretation from the curves plotted.

Temp C	304	310
100	16.3	15.4
200	16.7	15.6
300	17.1	16.1
400	17.6	16.6
500	18.0	17.0
600	18.3	17.1
700	19.0	17.6
800	20.0	18.0

The units are 10^-6 x C^-1

Thermal Conductivity

Temp C	304	316	310
200	15	13.5	12
400	17.5	16	14
600	18	18.5	17

The units used on Fig 29 of the INCO publication are kcal/m.hr.degC

Specific Heat

Temp C	301	316
20	456	452
90	490	486
200	532	528
320	557	548
430	574	565
540	586	573
650	599	586
760	620	615
870	645	649

The units are J/kg.K

Electrical Resistivity

Temp C	304	316	310
20	72	74	94
90	78	79	100
200	86	87	105
320	95	93	111
430	102	99	116
540	108	104	120
650	114	110	124
760	118	-	127
870	125	-	129

Units are micro-ohm.cm

Physical property units

A description of some of the units mentioned here is shown in the related article:

Ambient temperature physical properties of stainless steels to BS EN 10088-1

 

 

Source: http://www.bssa.org.uk/