INTERNATIONAL RESEARCH JOURNAL OF ENGINEERING AND TECHNOLOGY (IRJET)
E-ISSN: 2395 -0056
VOLUME: 04 ISSUE: 02 | FEB -2017
P-ISSN: 2395-0072
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Micro Structure analysis of TIG Welded SS 301 Alloy K Sreedhar1,J Nithin Kumar2, K Jithendar Reddy3, 1,3Assistant
Professor, Mechanical Department, GCET, Hyderabad, India Professor, Mechanical Department, GCET, Hyderabad, India ------------------------------------------------------------***--------------------------------------------------------------------2Assoc.
Abstract: This work deals with micro structure
power source with a high frequency generator. This produces a small spark that provides the initial conducting path through the air for the low voltage welding current. The arc generates high-temperature of approximately 6100 C and melts the surface of base metal to form a molten pool. A
analysis of TIG welding SS 301 plates of dimension 200*75*6 mm were taken, the. The input parameters are root gap, current, electrode diameter and gas flow rate. The main effects plots were plotted using Minitab software .the analysis is done with analysis software. Keywords: TIG welding, SS, Hardness, root gap, S/N Ratio.
welding gas (argon, helium, nitrogen etc) is used to avoid atmospheric contamination of the molten weld pool. The shielding gas displaces the air and avoids the contact of oxygen and the nitrogen with the molten metal or hot tungsten electrode. As the molten metal cools, coalescence occurs and the parts are joined. The resulting weld is smooth and requires minimum finish.
1. INTRODUCTION
GTAW welding is an electric arc welding process, in which the fusion energy is produced by an electric arc burning between the work piece and the tungsten electrode. During the welding process the electrode, the arc and the weld pool are protected against the damaging effects of the atmospheric air by an inert shielding gas. By means of a gas nozzle the shielding gas is lead to the welding zone where it replaces the atmospheric air. TIG welding differs from the other arc welding processes by the fact that the electrode is not consumed like the electrodes in other processes such as MIG/MAG and MM. Stainless steel is widely used in sheet metal fabrication, especially in automotive, chemical and rail coach manufacturing, mainly due to its excellent corrosion resistance and better strength to weight ratio. Stainless steel is a generic name covering a group of metallic alloys with chromium content in excess of 10.5 percent and a maximum carbon content of 1.2 percent (according to European Standard EN 10088) and often includes other elements, such as nickel and molybdenum. Due to formation of a passive layer, this is 1 to 2 nanometers thick; this metal exhibits excellent corrosion resistance. The passive layer is selfhealing, and therefore chemical or mechanical damages to it re-passivity in oxidizing environments. Stainless steel has been widely used for rail vehicle body shell design for many years owing to its corrosion resistance, low life-cycle cost, and high strength-to weight ratio and fire resistance. 1.1 Working Principle of TIG Welding Operation TIG is an arc welding process, as shown in Fig. Wherein coalescence is produced by heating the work piece with an electrical arc struck between a tungsten electrode and the job. The electrical discharge generates a plasma arc between the electrode tip and the work piece to be welded. It is an arc welding process wherein coalescence is produced by heating the job with an electrical arc struck between a tungsten electrode and the job. The arc is normally initialized by a
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Impact Factor value: 5.181
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Figure 1 working principle of tig welding
2.EXPERIMENTAL PROCEDURE In this work, SS 301 alloy of dimension 200*75*6mm was taken and the number of pieces were 18.Tig was performed the number of experiments were 9, the process parameters are Root gap, Current, Electrode and Gas flow rate
2.1 SS 301 chemical composition Carbon Chromium Iron Manganese Nickel Phosphorus Silicon Sulphur
0.0582% 16.0600% 72.6000% 1.9300% 6.5600% 0.0649% 0.3670% 0.005%
2.2 Common Applications of 301 Stainless Steel
Aircraft structural parts Trailer bodies Architectural (roof drainage/door frames, etc.) Auto body trim and wheel covers Utensils and table wear Conveyor parts
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