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Construction of Steel Railway Bridges
Published in John F. Unsworth, Design and Construction of Modern Steel Railway Bridges, 2017
Shop welds for steel superstructures may be made by the submerged arc welding (SAW), shielded metal arc welding (SMAW), flux cored arc welding (FCAW), gas metal arc welding (GMAW), electroslag welding (ESW), or electrogas welding (EGW) processes. FCM must be fabricated using SMAW, SAW, FCAW, and/or, if approved by the design engineer, GMAW processes using metal cored electrodes. ESW and EGW processes are not permitted for FCM fabrication.
Arc rotating behavior of SRA EGW in AH36 steel
Published in Materials and Manufacturing Processes, 2020
Yong Chen, Xiusheng Sun, Tao Zhang, Qintao Li, Shouyong Ni, Chenfu Fang
Electrogas welding (EGW) is the main method for the large structure vertical welding in shipbuilding. Wang et al.[1] studied the sidewall penetration by single-wire EGW and pointed that the greater arc heating spot, the more heat input and the oscillating welding torch were the important factors to increase the sidewall penetration in single-wire EGW process. However, when the plate thickness increased further, the problems of insufficient sidewall penetration arose. Sasaki et al.[2] adopted two-electrode in EGW process and showed that more heat input in two-electrode EGW process can increase the sidewall penetration. Therefore, the welding plates were increased in thickness, correspondingly.[3,4] Nevertheless, the excessive welding heat input would lead to insufficient impact toughness of welded joints. Bypass EGW came into being in this case.[5–7] It was the same as the two-electrode EGW process that two arcs were generated, but the arcs in bypass EGW included the main arc generated between the main wire and the base metal and the auxiliary arc generated between the main wire and the auxiliary wire. Therefore, a part of the heat flowed into the base metal.[8,9]