PR-650-174516-R01 Corrosion Resistant Weld Overlays for Pipeline Installations

Pipeline failure due to corrosion is a common problem in the oil and gas and petrochemical industry. A cost-effective way to prevent these failures is the application of corrosion-resistant weld overlays (WOLs) onto the internal surface of line pipe. A WOL is a deposition of a filler metal - such as a nickel-base alloy - onto the surface of a part - usually carbon or low alloy steels - to introduce desired surface properties to the original substrate [1]. As such, the service life of the substrate is increased which results in reduced costs to industries such as oil and gas and petrochemical as well as to the environment. WOLs are commonly created using arc welding processes such as cold wire and hot wire gas tungsten arc welding (CW-, HW-GTAW), gas metal arc welding (GMAW), and submerged arc welding (SAW).

Previous research performed at OSU indicates that a low heat input GMAW process, such as cold metal transfer (CMT), can produce WOLs which corrode up to ten times slower than overlays produced with CW-GTAW [2, 3], with up to four times higher deposition rates [4]. However, the majority of research into WOLs produced with the CMT process has been done with respect to nuclear applications, so there is a need for process optimization directed towards oil and gas applications. This project investigates the potential of CMT as an alternative to HW-GTAW for use with nickel-base alloys 625, 686 and 825 clad onto low alloy steel X65.