AR400, is a high carbon steel with a nominal hardness of 400 and a minimum Brinell hardness of 360 to 440. Wear-resistant steel is made by quenching and tempering forged steel plates.
Quenching occurs by heating the steel to a high temperature between 1,500 and 1,650°F and then rapidly cooling it with water. During tempering, the steel is again reheated below the critical temperature, from 300 to 700°F, and then cooled to room temperature. The quenching process creates a crystal structure within the steel, increasing its hardness, while tempering increases the steel's overall durability. The quenching and tempering process changes the grain structure to improve toughness and formability, resulting in a fully hardened material.
