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).
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.
Unlike martensitic steels, the austenitic stainless steels are not hardenable by heat treatment as no phase changes occur on heating or cooling. Softening is done by heating in the 1050/ 1120�C range, ideally followed by rapid cooling.