The Preparation And Characteristics Of Islandlike Tinplate With Phenolsulfonic Acid System

Du to tin resources are becoming more tight and experience in the international market,decreasing tin content of tin plate has become the development trend of tin plating process。However,the decrease of tin content often leads to the decrease of solderability and corrosion resistance.This paper investigate directly islandlike tin plating process and islandlike tinplating process on Ni-diffusion layer。Islandlike tin plating whose coating weight is less than 1g/m2 is one kind of lightly tin-coated steel(LTS).Due to the raised structure,islandlike tinplate holds maximum tin content after melting resulting in better coating weldability.At present,there are few reports about Islandlike tin at home and abroad,so that islandlike tinplate has good prospects for development.This article focuses on the research of the Phenolsulfonic acid islandlike tin plating technology and tin deposition process system.By electrochemical work station,SEM,and other methods,determine process parameters of the directly islandlike tin plating and islandlike tin plating on Ni-diffusion layer,and study the weldability and study the nucleation process of two kind of islandlike tinplate.Directly Islandlike tinplate was prepared by low additive and low current density.the concentration EN+ENSA is 0.5g/L,the current density is 1.4A/dm2,SnSO4 concentration of solution is 51g/L,temperature is 45℃.The SEM test shows that the size of the tin particles is in micron size,the minimum particle size is 0.64μm,the maximum particle size is 3.64μm,the average particle size is 1.95μm,and the coverage of tin is 53%.Islandlike tinplate holds more than 0.3g/L tin content after melting resulting in better coating weldability.Another islandlike tinplate is prepared on the Ni layer after heat treatment.The nickel content is 0.05g/m2,the heat treatment temperature is 450 ℃,the heat treatment time is 45 s,he concentration EN+ENSA is 5g/L,the current density is 2.8A/dm2,SnSO4 concentration of solution is 51g/L,temperature is 45℃.The SEM test shows that the size of the tin particles is in micron size,he average particle size is 1.64μm,nd the coverage of tin is 41%.The tafel curves and electrochemical impedance sprctroscopy(EIS)are used to analyze the corrosion resistance and found that islandlike tinplate on Ni-diffusion layer possesses the best corrosion resistance.Islandlike tinplate on Ni-diffusion layer also holds more than 0.3g/L tin content after melting resulting in better coating weldability.The EDS test shows that the rich carbon area is the active area of tin deposits compared with the lean carbon area.Iron electrode deposited in the Phenolsulfonic acid tin plating system is controlled by diffusion and its nucleation mechanism is closer to the instantaneous nucleation.The rich nickel area is the active area of tin deposits compared with the lean nickel area.Ni-diffusion layer electrode deposited in the Phenolsulfonic acid tin plating system is controlled by diffusion and its nucleation mechanism is closer to the instantaneous nucleation.