Case Study - 1: Crevice Corrosion in a Gear Assembly


Type of Faliure Crevice corrosion
Material ASM 6263 Steel
Environment Lubricants

 

Causes

Crevice induced pitting The failure was due to pitting induced by crevice between the sliding surfaces. The pitting occurred is a localized one. The formation of differential aeration cell in the crevice between the mating surfaces lead to the formation of pits.

The initiation of pitting is mostly confined to the pitch lines or areas above and below the pitch line. Pitting caused by surface contact is the consequence of surface contact fatigue. The cumulative effect of fatigue cracks results in the surface damage leading to pitting, which is accelerated by crevice.

 

Prevention

Use AMS 632 Steel, carburize, harden and temper to specifications for application.