Volume 4B expands coverage on equipment, control, troubleshooting, and problems associated with steel heat treating. New articles extensively address distortion and the prevention of cracking - including the modeling and simulation of distortion. Furnace equipment and controls are described in detail, along with quenching systems and characterization of quenchants for reliable and effective hardening. Gneral process and procedure factors are also introduced - including temperature uniformity of furnaces, calculation of heat treating costs, decarburization, and more.