-- Coated exhaust valve spindle of diesel engine using the mixed coating compositions of Inconel-Ni-Cr system and the coating method for improving corrosion resistance thereof

摘要

The present invention relates to an Inconel-nickel-chromium-based coating mixture for improving corrosion resistance of an exhaust valve spindle for a diesel engine, an exhaust valve spindle coating method using the same, and an exhaust valve spindle coated with a coating mixture, HVOF spray coating of a coating mixture containing Inconel 625 nickel alloy powder, nickel-chromium cermet powder and basalt mineral powder on the head bottom and neck of the exhaust valve spindle forms a dense and homogeneous coating film, So as to have high temperature corrosion resistance. A pretreatment step of ultrasonic cleaning the head bottom and neck of an exhaust valve spindle for a diesel engine to remove surface impurities; A surface treatment step of forming irregularities on the surface of the base material by blasting the head bottom portion and the neck portion of the spindle from which surface impurities are removed with Al ₂ O ₃ powder; And coating the coating mixture on the uneven surface with HVOF coating to form a coating film, wherein the coating step comprises 40 to 60 vol.% Of Inconel 625 nickel alloy powder, 30 to 40 vol.% Of basalt mineral powder, , And 10-20 vol.% Of a nickel-chromium cermet powder.