METHOD OF STEEL PARTS MANUFACTURE Russian patent published in 2002 - IPC

FIELD: energy efficient methods of manufacturing parts from carbon and alloyed steels with high operating resistance to corrosion and wear; applicable in agricultural, metallurgical, machine building and other industries in metal surface impregnation. SUBSTANCE: method includes heating, holding in nitriding gas medium and cooling. Additionally introduced is operation for surface preparation by method of degreasing for 5-15 min. Holding at thermochemical treatment is carried out with addition of carbon-containing gas at temperature of 560-680 C for 0.5-5 h up to formation of wear-resistant carbonitrile layer, and cooling is combined with oxidation and effected from temperature of holding in two stages - first, in air for 1-60 s and then in cooling medium. Technical result consists in that method allows increase of depth of protective coating up to 5 mcm and its adhesion strength with initial material, change of stressed state of surface layer by building-up of compression stress, increase of diffusion zone depth up to 0.6 mm, prevention or reduction of embrittlement effect of coating on material properties. EFFECT: higher operating resistance of parts from carbon and alloyed steels to wear, corrosion, saving in power during process of parts protection. 2 tbl, 1 ex