Abstract. Ultrafine-grained S322750 superduplex stainless steel has been obtained through high-pressure torsion (HPT) process. Microstructural evolution after the severe plastic deformation (SPD) shown no phase transformation. Isothermal heat treatment was applied process in order to promote secondary precipitation. Precipitation enhanced ultrafine-grained comparison coarse-grained at same isot...

This study investigated the microstructures of pearlite and martensite transformed from ultrafine-grained austenite in 0.45C steel and Vadded 0.45C steel. The mean prior austenite grain sizes were refined to be 4.5 μm in the 0.45C specimen and 2.4 μm in the V-added 0.45C specimen through cyclic heat treatment of austenitizing and water quenching, i.e., repetition of martensite § austenite trans...

True stress (·)­true strain (3⁄4) relationships until just before fracture, i.e., the plastic deformation limit, were estimated by the stepwise tensile test and the Bridgman equation for various metals and alloys with different crystal structures. The estimated ·­3⁄4 relationships were different from the nominal stress­strain curves including the conventional tensile properties. In the relation...