International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN (P): 2249–6890; ISSN (E): 2249–8001 Vol. 10, Issue 3, Jun 2020, 597-610 © TJPRC Pvt. Ltd.
WELD BEAD GEOMETRY AND SHAPE RELATIONSHIP IN SUBMERGED ARC WELDING USING RECYCLED SLAG DEEPANJALI NIMKER & REETA WATTAL Scholar, Department of Mechanical Engineering, Delhi Technological University, Delhi, India ABSTRACT Submerged Arc Welding (SAW) is the most versatile method in the Automation industry which is diligently working on the concept of waste utilization and energy saving. During SAW, the flux melts and converts into non-biodegradable product known as slag. This slag is then recycled and thus proves to be an important measure in reducing waste. Slag consumption will not only prevent environmental pollution but also proves economical. When additives/ deoxidisers and binders were added to slag, it rejuvenates the workability, mechanical properties, metal integrity and bead quality of the welded specimen. In this paper, an attempt has been made to formulate slag equivalent to fresh flux and then pertained to study its effects on bead geometry shape relationship of mild steel bead on plate. For this, Response Surface Methodology (RSM) technique was adopted and mathematical models were developed to relate the input parameters (wire feed rate, arc voltage, travel speed and nozzle to tip distance) with response parameters (such as bead width, bead height, bead checked for adequacy using ‘F’ test and ‘t’ test, respectively. Adequacy test revealed that newly designed slag proves beneficial in presaging the weld bead quality. Also, the RSM approach helps in selecting optimum process controllable variables. KEYWORDS: Slag Recycling, RSM, WPSF & WRFF
Original Article
penetration, weld penetration shape factor {WRSF} and weld reinforcement form factor {WRFF}). These models are then
Received: Mar 01, 2020; Accepted: Mar 21, 2020; Published: May 21, 2020; Paper Id.: IJMPERDJUN202055
INRODUCTION Now-a-days, the aim of automation industry is to recycle and utilize all their waste products in order to endure in this environment. SAW is contributing towards the concept by the use of slag as fluxduring welding. Recycling of slag was first attempted by using closed loop process [1] followed by the process of slag reclaimation[2]. Later, slag was recycled by adding deoxidisers and binderto it. This agglomerated slag was then subjected to welding where the physical and chemical properties of weld metal were evaluated and compared with welded specimen obtained using fresh flux. It was observed that weld chemistry, mechanical properties, microstructure and weld bead geometry were in accordance with AWS standard and thus, yields satisfactory performance [3-6]. Similarly, effect of recycled slag was investigated on stainless steel claddings and contributes to high quality weld bead along with cost saving upto 73% [7] and 70.73% in another research while welding mild steel plates [8]. During welding, there are many factors which affect the bead geometry of weld metal out of which current, electrode polarity, electrode diameter and electrode extension primarily affect the bead width, bead reinforcement and weld penetration. In this study, it was found that by the application of high current, straight polarity small electrode diameter and longer electrode extension it is possible to rise in melting rate of SAW [9]. Kiran et. al. [10] also reported the influence of wire current, current pluses and welding speed on bead geometry of HSLA steel and therefore concluded that the former two factors affect the weld bead width and reinforcement whereas weld bead penetration is affected by wire
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