英语翻译
Hot dip galvanizing is a process by which iron and steel can be treated to prevent rusting.In essence it involves dipping the article with a chemically clean surface into a bath of molten zinc which reacts with the iron and forms a coating.The principles have remained unchanged since galvanizing first became a trade more than 150 years ago,but a vast amount of research on all aspects of the process has enabled galvanizing today to be a techincally advanced industry.
Since molten zinc cannot react with iron or steel covered with mill scale or oil,the article to be galvanized must first be prepared for hot dipping by cleaning processes which may include degreasing,grit blasting and acid cleaning(pickling),The article next receives a coating of flux,which activates its surface to allow the zinc to wet it and react with it on immersion.When it is withdrawn surplus zinc drains back into bath.THe zinc coated article may be quenched by immersion in water(boshed) or simply cooled in air.
The two main processes used differ in the method by which the flux coating is applied.In the wet process the work after pickling and rinsing is dipped through a flux layer floating on the surface of the zinc bath.In the more common,dry galvanizing process a layer of flux is dried onto the work before dipping and the work immersed in a clear bath of molten zinc.