Weld Residual Stress Measurement Using Portable XRD Equipment in a Shipyard Environment

Weld residual stress plays an important role in the production and operating performance of ship structures. Various factors such as background noise, vibration, movement during ship construction, a layer of primer on the plate surface, and a layer of paint after ship construction bring challenges to measure weld residual stress in a shipyard. Three large test panels made of DH-36, High-strength low-alloy steel (HSLA), HSLA-65, and HSLA-80 steels were fabricated to examine the feasibility of using commercially available portable x-ray diffraction (XRD) equipment to measure residual stress in a shipyard environment. The measured results show that portable XRD equipment provided reliable measurements, with the shipyard environment effects, on the panels made of DH-36 and HSLA-65. On the other hand, the primer affected the accuracy of measured residual stress on the panel made of HSLA-80, but electro-polishing could have been used to remove the primer to achieve a good measurement.