Abstract
Freight truck shipping is a massive industry and an important contributor to the US economy. Truck axle shafts for decades have been made from induction hardened carbon steel with 0.4% to 0.5% carbon. Associated metallurgical engineering of steel procurements, forging, processing, and applied machining, impacts axle shaft production and performance. This paper reviews metallurgical principles and controls currently applied to heavy truck axle shaft use and production in North America. Basic metallurgical engineering principles and controls, as historically and currently applied and specified, plus potential opportunities for increasing engineering value optimization, are reviewed. In particular, case depth, surface hardness, microstructure, grain size, chemical compositional interactions, procurement, processing, metallurgical evaluation, and overall engineering characterization and achievement targets are discussed.
