Heat treatment involves the use of heating or chilling, normally to extreme temperatures, types of furnaces used in heat treatment pdf achieve a desired result such as hardening or softening of a material. The alpha iron has no spaces for carbon atoms to reside, while the gamma iron is open to free movement of small carbon atoms. The crystal structure consists of atoms that are grouped in a very specific arrangement, called a lattice.
In most elements, this order will rearrange itself, depending on conditions like temperature and pressure. When in the soluble state, the process of diffusion causes the atoms of the dissolved element to spread out, attempting to form a homogenous distribution within the crystals of the base metal. After heating the steel to the austenite phase and then quenching it in water, the microstructure will be in the martensitic phase. This is due to the fact that the steel will change from the austenite phase to the martensite phase after quenching. It should be noted that some pearlite or ferrite may be present if the quench did not rapidly cool off all the steel. Unlike iron-based alloys, most heat treatable alloys do not experience a ferrite transformation.