Which welding technique is best suited for repairing cracks in a high-stress WEC structural joint?

For repairing cracks in a high-stress Wave Energy Converter (WEC) structural joint, the Shielded Metal Arc Welding (SMAW), also known as stick welding, with low-hydrogen electrodes, is generally the most suitable technique, especially for on-site repairs. While other techniques like Gas Metal Arc Welding (GMAW) or Gas Tungsten Arc Welding (GTAW) can offer higher quality welds under controlled conditions, SMAW provides greater versatility and is less sensitive to wind and weather conditions, making it practical for offshore or exposed environments. The use of low-hydrogen electrodes is crucial to minimize the risk of hydrogen-induced cracking, a common problem in high-strength steels. Prior to welding, proper crack preparation is essential, involving grinding out the crack to create a smooth, beveled edge to ensure full penetration of the weld. Preheating the joint to the manufacturer's specified temperature is also necessary to slow the cooling rate and reduce the risk of cracking. Multi-pass welding techniques should be used to minimize heat input and residual stresses. After welding, post-weld heat treatment (PWHT) may be required to further reduce residual stresses and improve the weld's mechanical properties. The completed weld should be inspected using non-destructive testing (NDT) methods, such as ultrasonic testing or radiography, to ensure that it is free of defects. The selection of the specific welding procedure and filler metal should be based on the material properties of the WEC structure and the applicable welding codes and standards.