FIELD: mechanical engineering; metallurgy; agricultural production.
SUBSTANCE: method for improving the wear resistance of cast-iron working bodies of soil-cultivating implements using heat treatment. The method includes smelting, alloying and modifying cast iron, obtaining a casting in a sand, metal or ceramic mold, removing the casting from the mold at a given temperature, moving it into a liquid bath with a given temperature, characterized in that the casting is made from cast iron having the following chemical composition, %: C 3.2-3.3, Si 2.0-2.2, Mn 0.5-0.6, Ni 1.5-1.6, Mo 0.9-1.1, Cr 1.1- 1.3, Cu 1.2-1.4, Mg 0.04-0.05, Co 0.2-0.25, Ti 0.2-0.25, Ba 0.06-0.08, S≤ 0.08, R≤ 0.08, Fe - the rest, removed from the mold at a temperature of 950-1020°C and transferred to a bath of water with a temperature of 20°C, moreover, heat treatment is carried out by five cycles of immersion and extraction of the cutting part of the working body, and in the first cycle the cutting part is immersed in water and held for 3.5 seconds, then removed and kept in air for 2.5 seconds, in the second cycle it is immersed in water and held for 3.0 seconds, then removed and held in air for 2.5 seconds, in the third cycle immersed in water and held for 2.5 seconds, then removed and held in air for 6.0 seconds, in the fourth cycle immersed in water and held for 2.0 seconds, then removed and held in air for 13.0 seconds, in the fifth cycle immersed in water and held for 1.0 seconds, then removed and held in air until completely cooled, and in the first cycle the cutting part is immersed in water by 55%, in the second cycle the cutting part is immersed in water by 80%, and in the third and subsequent cycles the cutting part is immersed in water by 100%, while the values of the minimum section of the working body are in the range of 30-33 mm.
EFFECT: increased hardness and wear resistance of working bodies, zonal distribution of metallographic structures in functional zones.
1 cl, 1 tbl, 1 ex, 1 dwg
