Deformation strengthening and structure of structural steel upon shear under pressure

Microhardness measurements and electron and optical microscopy were used to study deformation distribution in samples of armco iron and structural ste els 20G2R, 30G2R, and 30KhGSN2A deformed by shear under pressure to a true logarithmic strain e = 7-10. The microhardness of all the alloys studied in creases monotonically from the center to the edges of the samples. The resu lts obtained are confirmed by the corresponding nonuniformity of the recrys tallized grain structure that arises upon annealing of deformed samples. No steady-state stage of deformation at which the hardness and the mean size of the substructure elements remain constant was revealed.