Enamel is an inorganic glass glaze coated and burned on the surface of metal blank. The enamel coating on the metal surface can prevent the metal from rusting, so that when the metal is heated, it will not form an oxide layer on the surface, and it can resist the corrosion of various liquids. Enamel products are not only safe and non-toxic, easy to wash and clean, but also widely used as tableware and washing utensils in daily life. Moreover, under certain conditions, enamel products are widely used because of their excellent properties such as high hardness, high temperature resistance, wear resistance and insulation. Enamel layer can also give products a beautiful appearance and decorate people's lives.