Hot-dip galvanizing, also known as hot-dip galvanizing, melts the zinc hot-dip galvanizing ingot at high temperature,

puts some auxiliary materials, and then immerses the metal component in the galvanizing tank, so that a zinc layer is

attached to the metal component. The advantage of hot-dip galvanizing is that its anti-corrosion ability is strong, and

the adhesion and hardness of the galvanized layer are better. The disadvantage is that the price is high, a lot of equipment

and space are required, the steel structure is too large and difficult to put into the galvanizing tank, the steel structure is

too weak, and the hot-dip galvanizing is easy to deform. Zinc-rich coatings generally refer to anti-corrosion coatings

containing zinc powder. Zinc-rich coatings on the market contain one zinc content. Want to know the thickness of zinc

can use the following methods

Magnetic method

The magnetic method is a non-destructive experimental method. It is carried out according to the requirements of

GB/T 4956. It is a method of measuring the thickness of the zinc layer by using an electromagnetic thickness gauge.

It is worth mentioning here that the cheaper the equipment may be, the greater the error may be measured. The price

of thickness gauges ranges from thousands to tens of thousands, and it is recommended to use good equipment for testing.

weighing method

According to the requirements of GB/T13825, the weighing method is an arbitration method. The plating amount of

the zinc coating measured by this method should be converted into the thickness of the coating according to the density

of the coating (7.2g/cm²). This method is a destructive experimental method. In the case where the number of parts is

less than 10, the purchaser should not reluctantly accept the weighing method if the weighing method may involve

damage to the parts and the resulting remedial costs are unacceptable to the purchaser.

Anodic dissolution coulometric method

Anode-dissolving a limited area of the coating with a suitable electrolyte solution, the complete dissolution of the

coating is determined by the change in the cell voltage, and the thickness of the coating is calculated from the amount

of electricity (in coulombs) consumed by the electrolysis, using the time to dissolve the coating and the Power

consumption, calculate the thickness of the coating.

Cross-sectional microscopy

Cross-sectional microscopy is a destructive experimental method and only represents a point, so it is not commonly

used, and is carried out in accordance with GB/T 6462. The principle is to cut a sample from the workpiece to be tested,

and after inlaying, use appropriate techniques to grind, polish and etch the cross-section, and measure the thickness

of the cross-section of the covering layer with a calibrated ruler.