What is the different between hot working and cold working?

Hot Working is done at temperatures above the recrystallization temperature of the metal, and Cold Working is done at temperatures below the recrystallization temperature of the metal.

What is metal cold working?

Cold working is the process of strengthening metals through plastic deformation. This is made possible through the dislocation movements that are produced within a material’s crystal structure. This is a technique commonly used in non-brittle metals that have remarkably elevated melting points.

What is warm working process?

Warm working, (or warm forming), is a metal forming process carried out above the temperature range of cold working, but below the recrystallization temperature of the metal. Warm working may be preferred over cold forming because it will reduce the force required to perform the operation.

What factors affect the recrystallization temperature of a metal?

Recrystallization Temperature

Increasing annealing time decreases recrystallization temperature.
Alloys have higher recrystallization temperatures than pure metals.
Increasing amount of cold work decreases recrystallization temperature.
Smaller cold-worked grain sizes decrease the recrystallization temperature.

What is warm working temperature?

Warm forging has a number of cost-saving advantages which underscore its increasing use as a manufacturing method. The temperature range for warm forging of steel extends from above room temperature to below the recrystallization temperature, which is about 800 to 1,800 degrees Fahrenheit, depending upon the alloy.

What are some of the advantages of warm working relative to cold working?

Indicate some of the advantages of cold working relative to warm and hot working. Advantages of cold working are: (1) better accuracy, (2) better surface finish, (3) increased strength due to work hardening, (4) possible directional properties due to grain flow, and (5) no heating of work required.

What is recrystallization temperature of a metal?

Process details The recrystallisation temperature for steels is typically between 400 and 700 °C. The recrystallisation conditions, such as heating rate and soaking time depend on the degree of cold work and the steel composition. The rate of softening increases rapidly as the annealing temperature reaches A1 point.

What’s the difference between hot working and cold working?

Cold working or work hardening is the process of strengthening a metal by plastic deformation at temperatures below the recrystallization temperature. The strengthening is obtained by dislocation movements of the metal structure. A dislocation is defined as a crystallographic defect in the metal crystal system.

When do you call a metalworking process hot working?

If the metalworking process is carried out above its re-crystallization temperature, it is called as hot working. Re-crystallization temperature is the temperature at which atomic mobility can be repaired when any defect was present in the metal caused by the working process.

What are the advantages of cold working metal?

1 Dimensional accuracy can be maintained. 2 No heating of metals. 3 Better surface finish can be achieved since there is no oxidation during the cold working of metals. 4 Strength and hardness of the metal are increased. 5 Due to cold working, metal gains strength and hardness. 6 Better strength and wear properties of the material can be achieved.

What are the advantages and disadvantages of hot working?

The hot working process is important in increasing ductility of metal. The yield strength can be reduced in this process. This allows working with metal easily. However, there are some drawbacks as well. Hot working can cause undesirable reactions to occur between the metal and the surrounding atmosphere.