Automotive Engine Piston Pin Anti-friction And Wear Properties

In order to improve the wear and friction resistance properties of piston pin, this paper chose 16Mn steel as test material and made the sulfide layer on the surface of piston pin by using the sulphiding on the basis of nitriding to lower its friction coeffiecnt and enhace the wear resistance, and optical microscope, micro-hardness equipment, SEM, EDAX, Taylor Hobson Precision Form talysurf series 2 and 19JC omnipotent tool microscope were used for studying the morphology and hardness profile of nitrided layer formed by plasma nitriding and carbo-nitriding at different temperature; analyzing the effect of temperature and atmosphere on the plasma S-C-N multifold treatment; exploring the friction coefficient and wear track morphology of the multifold sulphi- -ding samples, sulphiding samples on the basis of carburizing, and carburizing samples sliding against GCr15steel and LY12 aluminum alloy respectively; measuring the roughness and dime- -nsion change of piston pins before and after surface treatment. Results show: plasma nitriding at 520℃has better compositive properties in surface hardness, micro-hardness profile and diffuse- -on depth;520℃and the atmosphere of CS2:NH3=1:60 sulphidnig can form better sulfide layer;multifold sulphiding and sulphidng on the basis of carburizing can efficiently lower friction coe- -fficient, and improve the wear resistance and adhesion resistance. But the multifold sulphiding is slightly better than the sulphiding on the basis of carburizing. The results also display that multi- -fold sulphding increase the roughness of piston pin and the nitriding is the major reason of this increase, but the increase of roughness will not affect the wear and friction resistance properties of sulfide layer;multifold sulphiding has no effect on the deformation of piston pin, but cause the diameter increase of piston pin by 0.02418mm, and the diameter can be controlled by reduceing the standard dia- -meter of piston pin before heat treatment by about 0.02418mm, so this technology is applicable.