Externally hard shaft - produced by deposition of corrosion-and wear-resistant weld metal on a mild steel base

摘要

Externally hard shaft particularly for a ship's propeller is fabricated from mild or forged steel, the whole or part of the peripheral surface carrying a weld coating of a corrosion and wear-resistant metal e.g. aluminium bronze or stainless steel, the outer surface of this coating being rolled or shot-blasted to increase the fatigue strength. Process greatly improves the length of life of the propeller shaft in sea water and hence cuts time in dry dock for repair or replacement.