Hybrid Laser Arc Welding for Thick Plate High Performance Steels

High performance steels were developed in a cooperative program between the Federal Highway Administration (FHA), the American Iron and Steel Institute (AISI), and the U.S. Navy Carderock Division of the Naval Surface Warfare Center. HPS70W high strength steel is currently being used in bridge structures. HPS is stronger than conventional 70W steel and has less than 15% of the sulfur and 60% of the carbon. The major advantages of HPS70W steel are comparably high strength, high corrosion resistance, low carbon equivalent, high toughness and useful length. While SAW methods produce high quality welds in high performance steels innovative welding methods are being sought in the marine, transportation, oil and gas industries to replace SAW do to the extensive time required to weld thick joints. For example, in bridge fabrication butt splices between standard mill plates with plate thickness greater than 3 inches can take up to 15 hours to weld depending on the length of the girder flange. The objective of the Phase 1 project is to establish HLAW for high performance bridge steels. The Phase I effort will focus on demonstrating the feasibility of applying HLAW to butt welding plates with a minimum thickness of 3”.