Study Of Interaction Between N~+-implanted 316l Stainless Steel And MoDTC Lubricant Additive

316L austenitic stainless steel is widly used in industrial production, because of its good toughness and corrosion resistance; however, its low hardness and poor wear resistance decreases the service life of the workpiece and limits its application. So it is of great significance for application of 316 L stainless steel to improve the surface hardness and the wear resistance through surface treatment.Ultrasonic cold forging technology was applied to fabricate the surface nanocrystalline layers on 316 L stainless steel, and then N ion was implantated with different doses with ISB700 type multifunctional coating machine. The tribological properties of samples lubricated with PAO-4 and Mo DTC were studied using TRN friction and wear testing machine. SEM, XRD and nano indentation were used to analysis the surface microstructure and mechanical properties, and AES and XPS were used to study the element in-depth distribution, composition and chemical bonding status in the friction reaction film on the surface of both samples and their counterpart. The results show that:（1） With increasing N ion implantation dose, the peak N concentrations are increased; when N ion implantation dose is 8 ×10¹⁷ ions/cm²,the peak N concentration is 31 at.%. When N ion implantation dose is no less than 2×10¹⁷ ions/cm², γN phase is formed in the implanted layer of specimens, which improves the mechanical properties, such as nano hardness and the elastic modulus.（2） Under Mo DTC boundary lubrication conditions, the contents of MoS₂ and Fe S in the friction reaction film formed on both samples and their counterpart balls are increased as the dose increased. The friction coefficient, wear rate of both the implanted samples and their counterpart balls are decreased due to the formation of the friction reaction film, which prevents the adhensive wear and abrasive wear.（3） Under the boundary lubrication conditions by PAO and Mo DTC, ultrasonic surface nanocrystallization decreases the friction coefficient of the implanted samples.