Tempering, normalizing, quenching, annealing, which cooling methods are used

Fire. Normalizing.

Quench. Tempering.

1. Annealing. A metal heat treatment process in which metal is slowly heated to a certain temperature, held for a sufficient amount of time, and then cooled at a suitable rate (usually slowly, sometimes controlled).

2. Normalizing. Normalizing is a metal heat treatment process in which the workpiece is heated to AC3 or above ACC3 or ACCM30 50, and after holding for a period of time, it is taken out of the furnace and cooled in air. The difference between normalizing and annealing is that the normalization cooling rate is slightly faster than the annealing cooling rate, so the normalizing structure is finer than the annealed structure, and its mechanical properties are also improved.

In addition, the external cooling of the normalizing furnace does not occupy equipment, and the productivity is high, so normalizing is used as much as possible instead of annealing in production.

3. Quenching. A metal heat treatment process in which a metal workpiece is heated to an appropriate temperature and held for a period of time, followed by a rapid cooling by immersion in a quenching medium. Commonly used quenching media are brine, water, mineral oil, air, etc.

4. Tempering. According to different requirements, low temperature tempering, medium temperature tempering or high temperature tempering can be used. Generally, as the tempering temperature increases, the hardness and strength decrease, and the ductility or toughness gradually increases.

1. The tempering uses a water-cooled cooling method, which will be quenched according to the metallurgical principle.

And normalization treatment and then put back to medium temperature immersion (aging) for a period of time, which can promote the precipitation of a part of the carbide, and at the same time can eliminate a part of the residual stress caused by rapid cooling, so it can improve the toughness and flexibility of the material.

2. Normalizing. Using the air cooling method, the steel components are heated to 30 50 above the AC3 temperature, and then kept warm for a period of time to be air-cooled.

3. Quenching is to choose the appropriate cooling medium according to the material (commonly used cooling medium is: oil, water, salt water, etc.).

4. The annealing adopts the cooling method of slow cooling.

Normalizing: Fine-graining of metal grains, usually in preparation for heat treatment for quenching or machining. Certain mild steels are available as a final treatment.

Annealing: Refines metal grains, removes stress, reduces hardness, and can process a variety of metal structures according to the holding time, usually in preparation for quenching and machining. Annealing wastes heat, and products that can be normalized are preferably normalized.

Normalizing and annealing are both heat treatment processes before quenching + tempering (quenching and tempering).

Heat treatment refers to a metal thermal processing process in which metal materials are changed on the surface or inside the material by means of heating, heat preservation and cooling in the solid state to obtain the required properties.

Normalizing. The heat treatment process of pearlite structure is obtained by heating steel or steel parts to an appropriate temperature above the critical point AC3 or ACM, maintaining it for a certain period of time and cooling it in the air.

Anneal. It is a heat treatment process in which the sub-eutectic steel workpiece is heated to 20-40 degrees above AC3, and after holding for a period of time, it is slowly cooled with the furnace (or buried in sand or lime cooled) to below 500 degrees and cooled in air.

Quench. This is a heat treatment process in which the austenitization of steel is cooled at an appropriate cooling rate, so that the workpiece undergoes unstable microstructure transformation such as martensitic in all or a certain range within the cross-section.

Tempering heats the quenched workpiece to an appropriate temperature below the critical point AC1 for a certain period of time, and then cools it in a way that meets the requirements to obtain the desired structure and properties.