Types of anti-corrosion processes for bolt surfaces
Created on：2024-08-06 22:17
The bolt belongs to a kind of fastener, the surface of the bolt has stainless steel, galvanized, nickel plating, etc., then, how to distinguish these bolts?
Distinguish by appearance
First of all, distinguish by color: stainless steel is the primary color of iron, galvanized screws are white, color, black, nickel-plated screws are silver.
1. Stainless steel screws are stainless steel, the color of stainless steel is mainly iron and carbon alloy, so the color is close to the color of iron;
2. Galvanized screws have white zinc, color zinc, black zinc, etc., so the color of galvanized screws is generally white, color, black;
3. The color of nickel-plated screws is related to nickel, generally showing a very bright silver.
Other distinguishing methods
1. Distinguish by magnets: stainless steel is generally not magnetic, can not be absorbed by magnets is stainless steel screws, galvanized and nickel-plated screws can be absorbed by magnets. 2. Distinguish by oxidizing agent: metal nickel has a strong passivation ability, electroplating can quickly generate a thin layer of passivation on the surface, so the surface of nickel plated screws has a passivation film, galvanized surface is a layer of zinc, stainless steel surface is nothing, can be distinguished by strong oxidizing agent.
3. Distinguish by strong acid and alkali: stainless steel contains chromium and nickel, has strong corrosion resistance, is not corroded by strong acid and alkali, nickel-plated screw surface has a passivation film, is corroded slowly by strong acid and alkali, galvanized screw is corroded fastest.
Summary: The way to distinguish stainless steel screws, galvanized and nickel-plated screws from the appearance is to look at the color of the screws, the color of stainless steel screws is close to the primary color of iron, galvanized screws are white, color, black, nickel-plated screws are very bright silver: in addition, magnets, oxidants and strong acids and alkali can also be used to distinguish stainless steel screws, galvanized and nickel-plated screws.