METHOD TO STRENGTHEN SURFACES OF STEEL ARTICLES Russian patent published in 1994 - IPC

FIELD: chemical-heat treatment of metals. SUBSTANCE: steel article surface is heated up to melting by charcoal electrode short electric arc of reverse polarity, then it is cooled down to phase transformation temperature and pressed to plastic deformation by cooled tool. Strengthening of all the surface is performed through several passes. Pitch between the passes is divisible to the width of strengthening zone. After completion strengthening in one direction they repeat the strengthening in opposite direction. EFFECT: steel article surface of high quality. 5 dwg