The Institute of Metal Physics has developed a new class of smart high-strength stainless austenitic steels with a shape memory effect (SME), which is caused by nanostructured epsilon-martensite and dispersed vanadium carbides . These steels have no analogs in Russia and abroad. After cold deformation, the shape of the product is restored by subsequent heating at 200--400ОC because of a reversible martensite transformation. The proposed steels have been made; and 1,000-mmwide and 2.5-mm-thick sheet products were rolled at the metallurgical plants in the Ural region.
Melting and rolling of the shape memory steels in air ensures manufacturability and high technological effectiveness. A unique combination of the steels’ properties---such as shape memory effect upon small deformation (5%); thermally controlled SME from 0 to 3%; high strength and plasticity characteristics (the ultimate strength up to 1.5 GPa, the yield stress up to 1.1 GPa, and the specifc elongation up to 30%)---makes these steels applicable in the weldless connection of steel pipes, for sealing of defects in the oil well casing pipes, and as temperature sensor actuators.
