Integrated composite treatment method for in-situ PVD film coating after alloy steel surface nitriding

The invention discloses an integrated composite treatment method for in-situ PVD film coating after alloy steel surface nitriding. Firstly, a matrix is ground, polished and subjected to ultrasonic cleaning, and then the surface of the matrix is subjected to plasma cleaning and etching through an arc enhanced type glow discharge technology; then, ion nitriding treatment is performed, and a nitriding layer is obtained; and finally, under the conditions of similar temperature and pressure, advanced plasma auxiliary arc film coating treatment is performed in situ, negative bias voltage is applied to the matrix, and a hard film is obtained on the nitriding layer. According to the method, due to the fact that storage and programming summarizing are performed on the same device, under the conditions of similar temperature and pressure, a PN-PVD composite treatment process is integrally performed, high-density plasma performs cleaning and etching on the matrix in the nitriding process, the nitriding speed is increased, and an electronic heating effect is also generated on the early growth stage of a film layer; and by means of the composite treatment process, the adhesiveness between a coating and the matrix is remarkably improved, the abrasion-resistant performance of the coating is improved, and the comprehensive performance of coating tools, molds and mechanical parts is effectively improved.