enhancements

adding properties to materials through a range of processes

metal is cold worked such as bending, rolling or hammering. the crystals within the metal are distorted and changed, leading to improved tensile strength in the worked area. it leaves distorted metal crystals resulting in less ductility, cracking or damage in the area worked but can be removed by annealing

makes work hardened metal easier to work with by making it less brittle and more ductile. done by heating the metal and then very slowly cooling it allowing the metal crystals to grow and slowly move into place. industrially it is carried out in a specific temp controlled furnace

produces a steel with an outer casing of greater hardness and resistance to surface indentation, while inner core retains the original softer properties. it provides better wear resistance and used on components such as vehicle camshafts, gears, bearings and valves

2 stages- carburising which changes the chemical composition and quenching that fast cools the process but not affecting inner core properties

heating medium and high carbon steels alter the crystalline structure. holding them at this temperature for a given time then quenching them in water, oil or salt water baths. hardening and quenching greatly increases the hardness property but increases the brittleness of the material.

heat treatment process for medium and high carbons that is carried out after hardening to reduce some of the hardness and increase the toughness. an increase in ductility and decrease in brittleness is also made. it is done by heating below the critical point and slowly air cooled.