1. Chrome-plated thin steel plate
Chromium-plated thin steel sheet, also known as chrome-plated tin-free steel sheet, or chrome-plated sheet for short, is a substitute material for tin-plated sheet developed to save tin.
(1) Structure of chrome-plated plate
The chrome-plated plate is composed of a steel substrate, a chromium layer, a chromium oxide layer and an oil film layer.
(2) Performance and usage of chrome plate
①The corrosion resistance of chrome-plated sheet is slightly worse than that of tin-plated sheet. The thickness of the chromium layer and chromium oxide layer of the chrome-plated plate is more than 20 times that of the tin layer and the oxide film layer of the tin-plated plate. This film cannot protect the steel base from strong acid and strong alkali corrosion, but it can protect against weak acid and weak alkali. To be on the safe side, paint inside and outside is required before use.
② The adhesion of chrome plate to organic paint is particularly good, which is 3~6 times higher than that of tin plate to various paints. For example, epoxy phenolic paint 214#, two coats and one bake, is considered good when the surface adhesion of the tinplate is 5-6MPa, but the same paint with the same thickness, the minimum adhesion on the chrome plate is above 20MPa. When baking chrome-plated paint, it is not necessary to consider the limit temperature of heating due to the low melting point of tin (232°C) like tin-plated plates. A higher baking temperature can improve the productivity of coating and printing .
2. Galvanized steel sheet
Galvanized thin steel sheet is referred to as galvanized sheet, commonly known as white iron sheet, which is a low-carbon thin steel sheet coated with a layer of zinc with a thickness of more than 0.02mm as a protective layer, so that the corrosion resistance of the steel sheet is greatly improved. According to the production method, galvanized sheets are mainly divided into hot-dip galvanized sheets and electro-galvanized sheets. The zinc coating of hot-dip galvanized sheet is relatively thick, accounting for the vast majority of the output of galvanized sheet; the electroplating station sheet has a thin coating, which is mainly used as the bottom layer of plastic or paint.
3. Low carbon thin steel plate
Low-carbon thin steel plates refer to thin steel plates with a carbon content of <0.25%. Mainly used to make metal packaging containers. Among them, the painted black iron sheet has begun to be used in food and beverage cans. The inner wall of the tank should be coated with special organic paint, and the outer wall of the tank should be printed with colored ink. Painted black iron is also used for glass bottle caps.
