Which of the following galvanizing process used for intricate sha

SOLUTION

Sherardizing

• This process is used for galvanizing of those small parts having intricate shapes
• In this process, there is a box or container having filled with fine zinc powder
• The parts are placed in this box, surrounded by the powder; The box is then heated in an oxygen
• Zinc powder vaporises; Zinc vapour comes in contact with the surface of workpiece and zinc is deposited on the workpiece
• The workpiece is then taken out and it is allowed to cool down to room temperature; In this way galvanizing of the workpiece can be completed

Hot Dip Galvanizing

• The first step of this process is cleaning of the workpiece that involves its degreasing by acid rinsing followed by water cleaning
• The second step is its annealing and cooling in an oxide-free atmosphere
• During cooling when the temperature of workpiece reaches near to the temperature of molten zinc bath temperature' The workpiece is dipped into the bath
• The very thin and uniform coating layer can be maintained by passing the sheets through rollers just after the coating
• This method is not recommended for galvanizing of very delicate and complex shaped parts having complex interior designs

Flow Galvanizing

• This process is suitable for galvanization of flat sheet Metal Coating Processes metals only
• The limitation of dipping very large workpiece in hot-dip galvanizing is overcome; It also maintains a thin and uniform thickness layer of coating

Electroplating Galvanizing

• This process is time-consuming, so it is not recommended for mass production; Thickness of the coating layer is very thin so it is not capable to provide corrosion-resistant property to the workpiece