Development of Automatic GMAW Setup for Process Improvements: Experimental and Modeling Approach

Abstract

Gas metal arc welding (GMAW) offers highly efficient and low-cost welding, but manual movement of torch affects the uniformity of bead geometry, penetration, and heat input. In the present work, an indigenous automatic movement setup is designed and fabricated for GMAW. System behaviors like drive motor response, carriage, and wheel movement are studied through bond graph modeling. Welding time and welding velocity obtained from simulation are used to obtain the deposition efficiency during weld bead deposition on low carbon steel and stainless steel workpieces. Spatter index is also calculated for both the materials. Welding performance of automatic welding is compared with manual movement welding, and automatic welding is found capable to offer high deposition efficiency, low spatter index, uniform depth of penetration, and lower distortion for both the materials. Variation in microhardness and metallurgical observations by scanning electron microscopy are carried out for microstructure analysis.

Effect of process parameters on toughness and metallurgical behaviour during uniaxial automatic gas metal arc welding of austenitic stainless steel AISI 316

“…The frame can be moved up and down to select and maintain the desired CTW distance. The system behaviour as obtained from the system modeling 2 through Bond Graph depicts that the motor speed stabilizes, i.e. steady state speed is reached within a very short duration after starting.…”

“…The welding machine setup is shown in Figure 1 and the setup details with the system capabilities can be referred from Bhattacharya and Bera. 2 Four process parameters namely welding current ( I ), welding voltage ( V ), welding speed (x·c), and shielding gas flow rate ( Q g ) are varied to study their effects on the joint impact strength, metallurgical behaviour of the joint and heat-affected zones (HAZ). Levels of each parameter are decided by depositing beads and investigating the bead shape and penetration.…”

“…2,3 Automatic welding is generally performed using robotic systems but a low cost automatic welding system with suitable control strategy ensures smooth material transfer and effectively preserves stability of the arc. 2,3 Austenitic stainless steel retains the austenitic structure at wide range of temperatures and finds almost 70% of the total stainless steel. This graded steel provides the best corrosion resistance, however, inferior in toughness than ferritic or martensitic stainless steel.…”

“…Levels selected for each process parameter during the study.motor speed and longitudinal velocity of carriage for two different cases as sample representation. It is seen fromFigure 3that motor speed and longitudinal velocity of carriage reaches steady state within 0.1-0.15 s. The model considers the backlash present in the gear reduction arrangement and friction that is present between the wheel and guide rail 2. Achieved uniform carriage speed ensures the welding at uniform speed and this enables welding of the plates with more uniform heat input rate (J/mm) and ensures uniform depth of penetration and joint strength throughout the welding length.…”

High-strength steel S960QC welded with rare earth nanoparticle coated filler wire

“…For example, modern welding techniques such as pulsed mode, spray metal transfer mode, globular transfer mode, and adaptive welding techniques have improved uniformity and precision in welding performances thereby improving joint properties and reducing joint flaws. Moreover, the usage of robots and adaptive welding methods have improved consistency of weld bead formation and productivity, as well as ease of transportation [21][22][23]. To obtain flawless joints of thick HSS plates by GMAW, the composition of the base metal and welding wire and the welding parameters have to be carefully considered.…”