Tag Salt bath

Salt bath treatment is a heat treatment method commonly used in engineering. It is a process of immersing metal parts or workpieces in a salt bath at high temperatures for heat treatment.

This method has a high heat treatment effect, which can improve and control the mechanical properties, heat resistance, and corrosion resistance of metal materials. At the same time, the heat treatment is often used for surface quenching, surface hardening, age hardening, and other processes.

Principle

Salt bath is to use the osmosis of salt solution under high-temperature conditions. Various salts are dissolved in water or under vacuum conditions to form a solution with a certain concentration. Metal parts and workpieces can be soaked in it for a period of time by heating the salt solution.

Over time, the surface of metal parts and workpiece materials reacts chemically with the salt bath to form a metal structure with good mechanical properties on the surface or inside. The heat treatment can obtain different modification effects according to different salts and different heating conditions.

During processing, temperature and time are two very important parameters. The temperature refers to it in the salt bath, which is usually carried out at a high temperature above 500°C. The higher the temperature, the better the treatment effect. Time refers to the amount of time the metal part or workpiece is immersed in the salt bath, the longer the time, the better the treatment will be.

In the process of heat treatment, reactions such as oxidation will occur, which will change the concentration and properties of the salt bath. At the same time, some salt stains will also occur, which need to be replaced periodically. In order to ensure the treatment effect and increase the service life of the salt bath, some stabilizers and additives can be added to the salt bath.

Application

It is widely used, mainly involving the processing of steel, aluminum alloy, copper alloy, and other metal materials. Common salts include sodium chloride, potassium chloride, calcium chloride, magnesium chloride, etc. Different modification effects can be obtained by choosing different salts and salt bath heating conditions.

• • Surface quenching
    Surface quenching is to immerse the surface of metal parts or workpieces in a salt bath under high-temperature conditions, and then take them out of the salt bath to cool immediately, so that a harder and brittle surface layer can be obtained, and the wear resistance and durability of parts and workpieces can be improved. Corrosion and heat resistance.

 

• • Surface hardening
    Surface hardening is immersing the surface of metal parts or workpieces in a salt bath heated to a certain temperature for a certain period of time, and then taking them out and cooling them rapidly to form a harder and tougher structure on the metal surface, thereby improving the hardness of parts and workpieces. service life.

 

• • Age hardening
    Age hardening is immersing metal parts or workpieces at high temperatures for a certain period of time, then cooling them rapidly and store them at room temperature to form an improved organizational structure. Age hardening can improve the strength, corrosion resistance and toughness of metal materials. Age hardening is widely used in the manufacture of metal materials such as tungsten, molybdenum, and aluminum.

Summarize:

Through the detailed analysis of the principle of this heat treatment, we can see that the heat treatment is a complicated process. By understanding the basic principles and applications of this treatment method, we can better understand the role of salt bath heat treatment, so that it can be better applied to actual production.

At the same time, in the process of salt bath heat treatment, parameters such as temperature, time, and salt bath concentration are very important and must be precisely controlled according to different characteristics of materials to maximize the treatment effect.