What Does Work Hardening Mean?
Work hardening, is the strengthening of a metal by plastic deformation. In the plastic region, the true stress increases continuously, meaning that when a metal is strained beyond the yield point, more and more stress is required to produce additional plastic deformation and the metal seems to have become stronger and more difficult to deform. This implies that the metal is becoming stronger as the strain (work) increases.
Work hardening is also known as strain hardening or cold working.
Corrosionpedia Explains Work Hardening
Work hardening is a process that can help to reduce the potential for cracking along the surface of a strengthened metal or metal alloy. By employing the process, it is possible to use metals in the creation of devices that are designed to withstand a specific amount of load for a certain period of time. Since work hardening is not a process that can be reversed, the strength is easily measured, making it possible to choose the right metal or alloy for the manufacture of the product.
Some metals like aluminum and alloys like austenitic stainless steels cannot be heat treated or tempered to a higher hardness. However, they can be work hardened by putting some energy into them by processes such as by peening, rolling, forging or drawing.
Disadvantages associated with work hardening make it undesirable in some situations. The metal will be somewhat less ductile after the treatment, making it unfit for the production of certain types of products. In addition, a great deal of force is required as part of the process, whether heat or cold is employed. The directional properties of the metal may also be adversely affected, another factor that may render the metal unusable for certain purposes. For this reason, work hardening may be desirable, based on the nature of the products that will be made from the metal, or be completely undesirable as an event that unintentionally occurs during a manufacturing process.