Breakthrough Welding Process for Pipe and Plate (2023-401-001)
Keyhole TIG USA, EWI, NSWC Carderock, NAVSEA
March 2023 – February 2024
NSRP INVESTMENT $150K
The objectives of the project include: 1.) perform acceptable pipe welds in stainless steel and other materials utilizing K-TIG in the appropriate thickness ranges for use in the shipyard and conforming to NAVSEA Technical Publication S9074-AQ-GIB-010/248 (Tech Pub 248); 2.) Document Procedure Qualification Records (PQR) and Welding Procedure Specifications (WPS) conforming to Tech Pub 248; 3.) Outline technology transfer and implementation plan for the NSRP shipyard.
Fincantieri Marinette Marine (FMM) seeks to speed the process of welding stainless steel panels and pipes as well as copper-nickel pipe and tubes by an order of magnitude. In addition to increased welding speed, reducing the time and material cost for fit-up must be done to keep pace with the needed welding speed increase. Keyhole TIG (K-TIG) Welding offers order-of-magnitude improvements in Panel, Pipe, and Tube Welding by allowing Single-Pass Welds in Stainless Steels and Copper-Nickel Alloys in Thicknesses Between 10 GA and ½”. Legacy manual Gas Tungsten Arc Welding (GTAW) speeds are 4-6 inches per minute (ipm), per pass, regardless of material thickness. Using K-TIG, this project will demonstrate speed increases up to 10-30 ipm, a 150-400% speed increase. In addition, K-TIG can make many of these welds in a single pass with a square butt prep, vastly reducing fit-up time and filler metal usage while substantially increasing first-time quality.
KEY DELIVERABLES / BENEFITS
The major benefit of implantation of K-TIG in new ship construction at Naval shipyards will be the reduction in cost, time, and materials associated with welding pipe and panels in the construction of new ships. There are few, if any, welding methods that can perform singlepass welds in square butt joint configurations with the speed and simplicity of the K-TIG system. Compared to manual and even mechanized legacy GTAW methods, K-TIG has the potential to reduce or eliminate costly joint preparation, eliminate the need for multiple passes to complete a
joint, increase first-time quality, and reduce operator skill to perform these historically difficult welds.
POINT OF CONTACT: Jason Sherman | Keyhole TIG USA | [email protected]