Selection of Process Parameters for Welding P91 Steel Pipes Using the Analytic Hierarchy Process

Many new materials have been developed to render efficient service in power utilities under increased duty conditions. In this work, optimal parameters for welding P91 steel pipes are tried to find out. Welding tests are performed utilizing varying processes and process steps. First, gas tungsten arc welding (GTAW) process is used to make ischolar_main welding and to fill the weld zone. Next, shielded metal arc welding (SMAW) is done. In each of these processes, process parameters are optimised using the Anal\ytic Hierarchy Process (AHP). It is observed that at the welding voltage of 15 Volt, welding current of 110 Amp and 40.5 mm/min weld speed, GTAW gives sound weld, while at a welding voltage of 24 Volt, 85 Amp welding current and 35 mm/min weld speed, flawless welding is obtained with SMAW process for P91 steel pipes.