Stress-strain model for ferritic stainless steels

Compared with austenitic or duplex stainless steels, ferritic stainless steels have no or very low nickel content. Therefore, their cost is lower and more stable than those of austenitic and duplex stainless steels, providing a more viable alternative for structural applications. They are also less affected by gradual yielding than their austenitic and duplex counterparts and thus retain elastic stiffness at relatively high stress levels more like their ordinary carbon steel counterparts. Existing stress-strain models, however, are less accurate in predicting stress-strain curves for ferritic stainless steels than for austenitic and duplex stainless steels. The paper collects a wide range of tensile test data for ferritic stainless steel coupons cut either from steel sheets or cold-formed hollow sections. Using the three basic Ramberg-Osgood parameters, stress-strain models are developed for both flat and corner ferritic stainless steels. The accuracy of the proposed models is verified by comparing their predictions with experimental stress-strain curves.