The invention discloses a method for preparing a NiCrBSi-
TiN gradient
composite coating abrasion-resistant belt on the surface of a
drill rod joint. The method includes the following steps that (1) surface pre-treatment of a base material is performed; (2) a gradient
coating is prepared, specifically, mixed
powder of each layer is prepared according to the proportions of NiCrBSi
powder and Ti
powder in each layer in a composite gradient
coating shown as follows, the mixed powder of each layer is put in a
grinding miller to be mixed, the powder is dried for 0.7-1.2 hours at the temperature of 100 DEG C to 110 DEG C before spraying, and then
plasma spraying of each layer is performed in sequence; and (3) induction remelting aftertreatment of the
coating is performed, specifically, the
drill rod joint is coated with a high-temperature
antioxidant coating material with the thickness being 0.2-0.3 mm after being subjected to composite gradient spraying, and then induction melting treatment is performed through high-frequency
induction heating equipment. According to the method, the
process operation is simple, the feasibility is high, the abrasion resistance is remarkably improved, and abrasion to the abrasion-resistant material is small.