There are several different options to consider for heat treating stainless steel. The specific application and the type of alloy will be major factors in determining which of the heat treatment methods are the most appropriate. Another factor that will need to be considered is the reason for the heat treating, which is influenced by the demands that will be placed on the component or the part.
There are several different options for heat treating stainless steel. They are always done in very specific conditions to avoid scaling, or the development of oxidation on the surface of the alloy has to be controlled. This is done by the use of specific atmospheres that eliminate the presence of oxygen, eliminating these issues.
Annealing
Used for many different metals, annealing is one of the possible options for heat treating stainless steel. In this process any work hardened stainless is heated to a temperature of more than 1040 degrees Celsius for most stainless alloys. This heating allows the recrystallizing of the structure of the stainless and brings it back to the original orientation, allowing the part to have no stress with the molecular structure.
There are different types of annealing including quench annealing, which uses water for a rapid cooling process. There is also process annealing which is completed on the ferritic and martensitic stainless steels. Unless otherwise indicated the typical annealing process is used on the austenitic stainless steels.
Stress Relieving
With some types of applications, and specifically for lower temperature relief from stress, heating at temperatures less than 400 degrees Celsius can be another process used. However, this is lower temperature can trigger the formation of carbides in the grains, which will lower corrosion resistance after the process is completed.
When heat treating stainless steel that is either a low-carbon steel or a stabilized stainless steel this can be a very effective option as the formation of carbide is much less likely to be an issue.
Another option that can be considered for heat treating stainless steel is higher heating, actually above the typical annealing temperature, followed by very fast cooling processes. As this is a more difficult process to maintain for large orders and high volume types of operations, it is less common for general parts and components.
There are many different options for heat treating stainless steel. Working with a specialized metal and brazing company can help to determine the process that is right for your specific part requirements.
