Gennemhærning

Gennemhærning is a Danish term that translates to "through-hardening" in English. It refers to a heat treatment process applied to steel where the entire cross-section of the material is hardened. This is typically achieved by heating the steel to a specific temperature above its transformation point, followed by rapid cooling (quenching) in a medium like water, oil, or air. The goal of through-hardening is to increase the strength, hardness, and wear resistance of the steel uniformly throughout its bulk.

The effectiveness of through-hardening depends on several factors, including the steel's composition, particularly its carbon content. Steels with higher carbon content are generally more amenable to through-hardening. The quenching medium and rate of cooling also play crucial roles, as they determine the microstructure formed and thus the final properties. Improper cooling can lead to residual stresses and potential cracking.

Applications for through-hardened steel are widespread and include components requiring high strength and durability, such as gears, shafts, tools, springs, and fasteners. The process allows for the creation of parts that can withstand significant mechanical stress and abrasion. While through-hardening imparts desirable properties, it can also reduce ductility and toughness, making the material more brittle. Therefore, it is often followed by a tempering process to reduce brittleness and improve toughness, while still retaining a significant level of hardness.