Shot Peening in the Oil Industry

Shot peening interconnecting threads is standard practice for oilfield and deep hole pipe connections which suffer immense pressure and stress, yet must retain the ability to be easily stripped and continuously re-assembled. Stainless steel is infamous for its ability to 'pick up' and stick to itself and other alloys (‘galling’) especially in the presence of heat or pressure. High alloy steels and Inconel show similar traits and this can cause seizure of critical parts. Shot peening can dramatically reduce galling by reducing the surface contact area and work hardening the surface.

Picture courtesy of DJ Racecars

Picture courtesy of DJ Racecars

Shot Peen for General Engineering

Shot peening is universally recognised as a cold working process suited to inducing compressive stress into the outer layers of many hard metal components. This dramatically increases the in-service fatigue life, since an elemental layer in compression cannot stress crack. Modern techniques use precision controlled high velocity ball shot to simulate the less consistent age-old method of repetitive hammer blows. Shot peening is standard practice for highly stressed items such as turbine blades, gears and automotive springs.