A Study on the Weldment Hardening Discrimination Procedure and Improvement of Flux Cored Arc Welding Process of ASTM A553-1 (9% Nickel Steel) Material Using Bead Geometry Distribution

As a result of strengthened sulfur content standards for ship fuel oil in IMO regulations, major domestic and foreign carriers have high growing demand liquefied natural gas (LNG) powered ships related equipment. For LNG operation cryogenic environment, storage tank supply system that uses steel with excellent brittleness fatigue strength is required. Ships use vulnerability to explosion fire. this reason, 9% Ni typically used, since requires quality products special materials structural technologies guarantee operability at temperatures. However, there an urgent need research derive uniform welding quality, process difficulty differences welder’s skills can cause deterioration the weld process. steel, higher dilution ratio base metal, lower strength. In order secure required strength, excessive metal should be avoided, relationship between investigated. According previous research, if it exceeds 25% may than API standard 363 MPa hardening welds. Therefore, study, flux cored arc performed by establishing criteria evaluated based on SVM method determine structure cured according rate metal. We would like propose multipurpose optimization algorithm ensure steel.