Inverse Hardening
Inverse hardening is a type of tempering that is used to make tools and other metal products more durable and strong, while increasing their resistance to wear. The process is also sometimes known as reverse annealing. Inverse hardening acts by selectively hardening the surface of a metal, typically through the use of an induction coil, while the core remains soft. This increases the overall strength and wear resistance of the metal product.
Inverse hardening works by applying a rapidly fluctuating magnetic field to the surface of the metal product, which induces electrical current flow. The current causes heat build-up in the metal’s surface, which can then be used to increase hardness. The metal is kept below its melting point, allowing it to be hardened to a specific range of hardness values while retaining its original properties and properties of the core material. The inverse hardening process can be used to create a more even and uniform hardness distribution.
Inverse hardening is suited to manufacturing processes in which a uniform surface hardness is necessary, such as gears, tooling and machine parts. It is undertaken after the metal has been heated, rolled and quenched to an appropriate temperature for the desired strength profile. Inverse hardening produces a more wear-resistant and wear-regulating surface than other methods, and allows manufacturers to keep closer-tolerances and produce better-performing, higher-end products.
Inverse hardening can be used on various metals, including carbon steel, stainless steel, copper-nickel alloys and copper-titanium alloys. However, the process works best on ferrous metals due to their inherent magnetic properties. The depth of the hardened surface layer can be adjusted by regulating the temperature and the strength of the applied magnetic field.
Inverse hardening is incredibly beneficial to a variety of industries, providing more wear-resistant, strong and reliable surfaces in a variety of tools and products. The process is a safe and cost-effective tempering technique, allowing manufacturers to produce better, longer lasting products.
