METHOD TO HARDEN SURFACE OF STEEL ITEMS Russian patent published in 1994 - IPC

FIELD: chemical- heat treatment of surfaces of steel items. SUBSTANCE: item surface is heated up to melt point by electric short-circuit arc of reverse polarity, and cooled down to phase transformation temperature, at which surface plastic deformation is carried out by cooled instrument. Chill treatment starts directly from deformation temperatures. As a result surface decarbonization is prevented. EFFECT: increased surface hardness and resistance to wear. 1 tbl