CrN coating was produced on YG6 substrate by DC magnetron sputtering at different nitrogen flow ratios.The morphology and element composition of the coating were analyzed by XRD,SEM and EDS,the hardness and adhesion of the coating were measured by digital microhardness tester and scratch tester,and the tribological properties of the coatings were investigated on the friction and wear testing machine.The results show that the structure of CrN/YG6 coating is relatively loose and presents columnar growth when nitrogen flow ratio (nitrogen flow in proportion to total gas flow) is 20% and 30%,and relatively compact and grows like triangular particles when the nitrogen flow ratio is 40% and 50%.With the increase of nitrogen flow ratio,the hardness of the coating is increased firstly and then decreased,and reaches the maximum value of HV1 752.5 when the nitrogen flow ratio is 40%.With the increase of nitrogen flow ratio,the friction coefficient of the coating changes little,while the wear is increased firstly and then decreased and then increased,which reaches a minimum of 2.03×10-8mm3/(N·mm)when the nitrogen flow ratio is 40%.It is found that the CRN coating has good comprehensive properties when the nitrogen flow rate is 40%.