Bråkjølingen
Bråkjølingen is a term used in Scandinavian languages, primarily Swedish and Norwegian, to describe a sudden and rapid cooling of a material, often metal, by submerging it in a liquid such as water or oil. This process is a critical step in the heat treatment of metals, particularly in hardening. When steel is heated to a specific temperature and then quickly cooled, its microstructure changes, making it harder and more brittle. The rapid rate of cooling is essential to achieve the desired hardness. The choice of quenching medium can influence the final properties of the metal; for example, quenching in oil results in a slower cooling rate than quenching in water, which can be beneficial for certain alloys or to prevent cracking.
The term "bråkjøling" itself literally translates to "noise cooling" or "violent cooling," referring to the characteristic