The terms hardening and tempering steel are often used together, but they are two different processes. In general, the name is indicative of the process, with hardening used to create a rigid, durable surface. Tempering is done, typically after the hardening process, to remove any internal stress created by the process as well as to make the steel part or component less brittle and more durable.
When considering the processes of hardening and tempering steel, there are specific considerations to keep in mind. Different options in both hardening and tempering produce different end results, so it is essential to start with the desired end properties of the part or component and work back into the specific processes that are best suited to achieve these results.
Both include heating and cooling of the part or component. The degree of heating, how long it is held at the specific temperature and the speed and type of cooling process used, from air cooling to quenching, are all essential factors to consider. The process of tempering is always at a lower heat and with slower cooling, allowing alignment of the steel molecules throughout the process.
The most common options in hardening and tempering steel include:
• Neutral hardening – this is the option when high degrees of hardness are required. This heats the steel to complete austenitizing, followed by quenching and tempering.
• Austempering – substituted for traditional types of quenching and tempering when high ductility and toughness is essential for the part or component.
• Induction hardening – hardens the surface layer of the part or component (case hardening) without any change to the interior structure of the steel.
• Double hardening – two specific processes that can include the first step of annealing followed by hardening.
Hardening, as well as tempering, can be completed in batch orders for easy scalability for large orders and for highly consistent end results.
VN:F [1.9.22_1171]Understanding The Basics Of Hardening And Tempering Steel,