Pulse nitrocarburizing surface treatment process and compounding process for inner sleeve of hydraulic coupler

The invention discloses a pulse nitrocarburizing surface treatment process and a composite process for an inner sleeve of a hydraulic coupling. The composite process comprises the following steps: 1) rough turning; 2) heat treatment; (3) semi-finish turning; (4) finish turning; (5) semi-finish turning; 6) fine grinding; (7) deburring; 8) pretreating the inner surface of the inner sleeve; and 9) pulse nitrocarburizing surface treatment: 1) inner sleeve cleaning; 2) charging; (3) pre-oxidizing; 4) nitrocarburizing: heating the inner sleeve part in the furnace to 560-580 DEG C, and keeping the temperature for 5-6 hours; meanwhile, a gas nitrocarburizing atmosphere of NH3 + CO2 is introduced into the furnace; and (5) cooling is conducted. According to the inner sleeve compounding process, the machining precision of the inner diameter of the inner hole of the inner sleeve is improved, and the machining efficiency of the inner sleeve is improved; the requirements of different friction coefficients can be met; the s