Thickness Inhomogeneity Of Winding-Plating Copper Layer On 316L Strip

It is necessary to decorate and protect its surface using copper plate in production,after the stainless steel strip was cut to a certain size.However,it is not suitable for continuous electroplating for short strip（≤2 m）,because it is too short.And,ordinary hanging plating requires large plating tanks and anodes.Therefore,it is designed a new structure of hanger to electroplating copper by winding in this paper.In addition,it is studied the thickness distribution characteristics of copper coating by winding,and the effects of different electrode spacing,current density,profiling anode and hanger on the surface morphology and thickness distribution of the coating.The microstructure of copper coating was characterized by metallographic microscope and scanning electron microscope.The copper coating can cover the strip depression with flat copper coating.The copper grain size is different,and the coating thickness distribution is uneven on the micro level.The copper coating is light yellow,bright and dense.The bonding ability and roughness of the coating were tested by bending method at room temperature and roughness tester.Keep bending the copper plated stainless steel until it is broken,and the coating on the section is free from falling off and peeling.The coating has good adhesion,while the roughness of coating Ra are 0.25μm.The copper layer surface is dense and bright.The uniformity of coating thickness distribution was improved by changing the electroplating process parameters:electrode spacing,profiling anode and current density.The improved electroplating process parameters:double nickel plate anode,nickel electrode spacing of 4 cm,current density of 2 A?dm^-2,temperature of 40 ^oC;Double profiling copper strip anode for copper plating,with electrode spacing of 3 cm,current density of 2 A?dm^-2and room temperature.The standard deviation of the thickness distribution of the improved front and back coating is 1.6μm、1.8μm.The uniformity of the front side is increased by 80.7%,and the uniformity of the back side coating is increased by 59.1%.The uniformity of coating thickness distribution was improved by improving the hanger structure and adding auxiliary cathode.The standard deviation of coating thickness distribution on the front and back of the improved scheme 6 hanger is 0.4μm、0.4μm.Compared with the above improved results,the evenness of the front and back is increased by75.0%and 77.8%respectivelyTo sum up,the designed cylindrical rack can be used to evenly plate stainless steel strip to obtain bright and dense coating.Moreover,by changing the electroplating parameters and upgrading the ranger structure,the standard deviation of the coating thickness distribution on both sides of the coil copper coating is reduced to 0.4μm.