To get the desired properties of metal materials, metallurgists would normally place them under heat treatment. Heat treatment is a group of industrial and metalworking processes that are used in changing and modifying the properties of a metal or any other material. The processes involved in heat treatment are constantly enhanced by different metallurgists to obtain improved results and achieve cost-efficiency.
Some Effects of Heat Treatment Processes
Heat treatment processes bring numerous effects to metal materials that undergo them. For one, some processes can make metal materials soft, while others can boost their overall hardness. Alternatively, the electrical and heat conductivity of numerous metal materials may also improve due to specific heat treatment processes. Even the chemical properties of these metals can be altered once they are placed under numerous heat treatment procedures. Stresses due to earlier heat treatment processes may likewise be alleviated and relieved once they are placed under other heat treatment processes.
Understanding the Technological Process
Understanding the technological process of heat treatment is key to the successful alteration and modification of metal materials. Most of the heat treatment processes are carried out by three essential steps: heating, heat preservation or holding, and cooling. These steps are usually interlinked. However, the inclusion of some of these steps would still vary based on the metal that is intended to be processed.
- Heating: Heating is typically carried out first when placing metals under heat treatment. This step is done in line with a prescribed thermal profile of a metal or an alloy under a controlled atmosphere through different heat sources such as liquid, gas fuels, and electricity. At this point in heat treatment, an alloy that is placed under the heating process may transform into one of three different states, which may be a mechanical mixture, a solid solution, or a combination of the two.
- Holding: Heat preservation or holding, alternatively, is the process where the metal is maintained at an achieved or preferred temperature. During the holding time, the surface temperature of a metal material is maintained for a certain time so that its internal and external temperatures would become consistent. Likewise, this specific step will allow the material to undergo microstructure transformation. The duration of this process depends on the requirements, the material type, and the part size of the material.
- Cooling: Cooling is crucial for heat treatment processes as it determines the outcome of the metal material. During the cooling process, the metal material is expected to undergo structural changes through the help of different cooling media like brine, water, oil, or forced air. Brine is known for its ability to absorb heat the fastest, while air is known as the slowest among the mentioned cooling media. The cooling requirements of metal materials would still depend, however, on their specific type and composition.
The effects of heat treatment processes may vary according to the composition of the metal and its overall condition. Steps and elements involved in a specific heat treatment process can also affect the outcome of a metal being processed and treated.