Surface Modification of 316L Stainless Steel with AlCrN Coatings for Heating Ventilation and Air Conditioning Equipment

The AlCrN coatings were synthesized by multi-arc ion plating on substrate of 316 L stainless steel,a material for fabrication of heating,ventilation and air-conditioning(HAVC) equipment.The influence of the substrate rotation speed on the microstructures,phases and tribological behavior was investigated with X-ray diffraction,scanning electron microscopy and mechanical tools.The results show that the rotation speed had a major impact.For instance,as the speed increased,the grain density of the AlCrN coatings decreased; the hardness increased,reaching a maximum of 3968 HV; the friction coefficient changed in a decrease-constant manner.A complete oxidation of AlCrN coatings at 700℃ significantly decreased the hardness and depleted the nitride phase,accompanied by an increase of friction coefficient from 0.455 to over 0.612.The thickness of the fairly compact AlCrN coatings was estimated to be 3.3 μm to 4.1 μm,and no columnar grain was observed.