A Review: Distortion Control in 20MnMoNi55 Material Using GTAW and SAW Process

Abstract

Gas tungsten arc welding (GTAW) is high quality and high precision welding process which is suitable for welding thin metals. Inert gases such as helium and argon, carbon dioxide, nitrogen etc. are used as shielding gases to prevent the weld bead from air, dust and other contaminations in welding. There are so many welding process parameters affecting the weld quality in GTAW. Important process parameters which mainly affect the weld quality are; welding current, arc voltage, welding speed, gas flow rate, heat input, and specimen thickness. Important quality parameters in GTAW process are depth of penetration and weld bead geometry. Depth of penetration and weld bead width, both are affected by welding speed. As welding speed increases, depth of penetration increases but weld’s bead width decreases. The weld joint quality can be assessed in terms of weld bead geometry, mechanical properties and distortion. Different shielding gases can give its effect on the weld penetration. This paper covers a review of different shielding gas proportions and their effect on the weld penetration. Shielded metal arc welding (SMAW) is a process that uses an arc between a covered electrode and a weld pool to accomplish the weld. As the welder steadily feeds the covered electrode into the weld pool, the decomposition of the covering evolves gases that shield the pool. The process is used without the application of pressure, and with filler metal from the covered electrode. The sound weld metal deposited by the process is used not only for joining, but also for applying a functional surface to metal products. In welding booths and shops, the linear metal rod with a covering is commonly referred to as a stick and the shielded metal arc welding process is popularly referred to as stick electrode welding