METHOD OF HEAT TREATMENT OF PARTS MADE OF METALS, STEELS AND ALLOYS Russian patent published in 2002 - IPC

FIELD: heat and thermochemical treatment of machine parts in various gas media, protective and saturating; applicable in machine building, aircraft and automobile and other industries. SUBSTANCE: method includes heating, holding and cooling of machine parts in airtight muffel of heat-treatment furnace. Muffel is evacuated and filled with protective atmosphere. Muffel is made airtight with help of seal with filler. Created simultaneously in airtight muffel and autoevacuation and protective atmosphere due to reaction of gases in muffel with surface of treated parts and seal operation. Included into seal filler are respective activators. Ratio of muffle working volume to area of treated parts surface is selected of not above 0.5 cu.m/sq.m. For parts heat treatment accompanied by diffusion alloying, preliminarily placed into muffel are respective substances of saturating elements. Use of the offered method of heat treatment of machine parts results in no change of their weight irrespective of grades of steels and alloys after heat treatment and decarbonization of parts surfaces. Offered method provides for intensification of diffusion alloying process by 2-4 times as compared with prototype. EFFECT: higher productivity and reduced labor input in parts heat treatment. 2 cl, 3 tbl