Simple heat treatments to produce ferrite and pearlite. Part 1: Full annealing and normalizing

Casting, welding, forging, rolling and other manufacturing processes may produce parts having nonuniform microstructures and, thus, nonuniform properties. An important example of this relationship is solidification segregation of the alloying elements in steel castings, which often results in poor properties. However, the proper heat treatment may enhance the properties of such castings and virtually eliminate the detrimental effects of nonuniform microstructures. In addition, many heat treatments, such as annealing, also soften the material, making the part less difficult to manufacture. Full-furnace annealing or spheroidizing heat treatments, for example, are generally given tool steels in order to make them softer, and to facilitate the manufacture of components. Tool steels are typically machined or ground to nearly the final size and shape, then heat-treated to achieve the final (usually very high) hardness. After hardening, the tool steel component can be lapped to its final dimensions.