STUDY ON THE FAILURES OF WELD JOINTS OF ROOF HOOPS & BIAS MEMBERS IN THE PROJECT JEWEL ROOF CONSTRUCTION AND APPLICATION OF FLUX-CORED ARC WELDING TO AVOID FAILURES

Abstract

During the construction of the roof structure of the commercial interconnection between the three airport terminals of the Changi Airport in Singapore, several failures have been noticed during the welding of roof hoops and bias members. In this context, experimental studies have been performed on transient heat transfer in welding distortion control by using flux-cored arc welding process (Self Shielded-SS) by using three(3)-dimensional welding in High Strength Low Alloy (HSLA) of 355\xa0MPa yield strength and 460\xa0MPa yield strength steels. The Flux-Cored Arc Welding process (SS) combines the versatility of shielded metal arc welding with the continuous and automatic electrode feeding feature of gas metal-arc welding. The process is economical and versatile, so it is used for welding a variety of joints, mainly on steels, stainless steels, and nickel alloys. The higher weld metal deposition rate of the flux-cored arc welding process (SS) has led to its use in the joining of sections of all thicknesses. The use of tubular electrodes with very small diameters has extended the use of this process to workpieces of smaller section size. A main advantage of using flux-cored arc welding (SS) is the ease with which specific weld-metal things can be developed. By adding alloying elements to the flux core, virtually any alloy composition can be produced. The process is easy to automate and is readily adaptable to flexible manufacturing systems and robotics.