QUENCHING

In materials science, quenching is the rapid cooling of a workpiece to obtain certain material properties. It is a mechanical process in which steel and cast iron alloys are strengthened and hardened. These metals consist of ferrous metals and alloys. This is done by heating the material to a certain temperature, depematerial. This produces a harder material by either surface hardening or through-hardening varying on the rate at which the material is cooled. The material is then often tempered to reduce the brittleness that may increase from the quench hardening process. Items that may be quenched include gears, shafts, and wear blocks.

 

Before the material is hardened, the microstructure of the material is a pearlite grain structure that is uniform and lamellar. Pearlite is a mixture of ferrite and cementite formed when steel or cast iron are manufactured and cooled at a slow rate. After quench hardening, the microstructure of the material form into martensite as a fine, needle-like grain structure.When quenching, there are numerous types of media. Some of the more common include: air, brine (salt water), oil and water. These media are used to increase the severity of the quench.