Surface hardening of steel | flame, induction, laser beam, case hardening and nitriding

In this video, we look at various processes for surface hardening (surface hardening, case hardening) in order to increase the wear resistance of components while the component core retains its toughness. The processes covered are flame hardening, induction hardening, laser hardening, case hardening and nitriding hardening. In flame hardening, a burner flame is passed over the material surface to heat it. Subsequent quenching leads to the formation of martensite, which results in increased hardness and wear resistance. Flame hardening is well suited to large components, but has its limits with small and complex geometries. During induction hardening, the workpiece is exposed to a high-frequency electromagnetic field to generate eddy currents and heat the surface. This process allows precise hardening depths and minimises distortion. It is particularly suitable for thin-walled workpieces, but requires a relatively high initial investment. However, the process can be easily automated. Laser beam hardening offers short heating times and minimal hardening distortion. A powerful laser beam heats the surface and self-quenching ensures high hardness. Ideal for hard-to-reach areas such a recesses or blind holes. In case hardening, low-carbon steel is carburised in a carbon-containing environment and then hardened. It allows the hardening of low-carbon steels and is suitable for dynamically stressed components. Nitriding uses special nitriding steels and nitrogen to form hard and wear-resistant nitrides on the surface. Unlike other hardening processes, there is no lattice transformation, which minimises component distortion. Nitriding also improves corrosion resistance and fatigue strength.

00:00 Surface hardening
01:28 Flame hardening
02:33 Control of the hardening depth
03:04 Advantages and disadvantages of flame hardening
04:21 Induction hardening
04:44 electromagnetic induction
05:32 Quenching
06:03 Controlling the hardening depth (skin effect)
07:07 Advantages and disadvantages of induction hardening
08:01 Laser beam hardening
09:26 Case hardening
10:36 Carburising and quenching
11:52 Nitriding