Comparative Evaluation of Mechanical Characterization Features of Dissimilar Weldments

An attempt has been prepared to join the two dissimilar materials AISI 310 and AISI 316 L by Tungsten Inert Gas (TIG) welding process. AISI 316L and 90 S was used as filler metal. The microstructures of AISI 316 L and AISI 310 were evaluated after the TIG welding. And also various mechanical tests were conducted on Weldments to evaluate the mechanical properties .In this paper, the focus is purely on characterization and analysis of the dissimilar metal welded joint. The chemical composition of base metals as well as filler metals was found to play an important role on mechanical properties. Mechanical tests such as SEM/EDS, optical micro micro-hardness, tensile test and fractrography are performed. And then a comparison is made between the results


INTRODUCTION
Welding is one of the most effective joining process employed in wide range of industrial application for joining of materials [1]. The dissimilar metal welded joints have been emerged as a structural material for various metallurgical and industrial applications which provides improved combination of mechanical properties like corrosion resistance, strength with lower cost. Selections of joining process for such a materials are very difficult because of their physical and chemical properties [5]. Dissimilar metal Weldments are generally used in various industries such as power generation, metallurgical, chemical @ IJTSRD | Available Online @ www.ijtsrd.com | Volume -2 | Issue -3 | Mar-Apr 2018 An attempt has been prepared to join the two AISI 316 L by Tungsten Inert Gas (TIG) welding process. AISI 316L and 90 S was used as filler metal. The microstructures of AISI 316 L and AISI 310 were evaluated after the TIG welding. And also various mechanical tests were uate the mechanical properties .In this paper, the focus is purely on characterization and analysis of the dissimilar metal welded joint. The chemical composition of base metals as well as filler metals was found to play an perties. Mechanical tests such as SEM/EDS, optical micro-structure, hardness, tensile test and fractrography are performed. And then a comparison is made between Dissimilar metal weld, TIG welding, AISI Welding is one of the most effective joining process employed in wide range of industrial application for The dissimilar metal welded joints have been emerged as a structural material for ustrial applications which provides improved combination of mechanical properties like corrosion resistance, strength with lower cost. Selections of joining process for such a materials are very difficult because of their physical 5]. Dissimilar metal Weldments are generally used in various industries such as power generation, metallurgical, chemical industry, electronics, boiler manufacturing and nuclear industries to take the benefit by combining the properties of different materials in a single component [2] The reported work have been described that there are many parameters that control the weld ability of dissimilar metals such as their crystal structure , chemical composition, solubility in the liquid and solid state. Spreading of filler metal in the weld pool area frequently leads to the creation of inter phases. Many of these inter-metallic phases are brittle and hard and affect the ductility of joint, mechanical strength of the joint and toughness. Tungsten inert gas welding is a joining process and it can be wildly used in modern industries for joining either similar or dissimilar metal Weldments. Tungsten inert gas welding is often known as gas tungsten arc welding (GTAW) .The advantages of tungsten inert gas welding like joining of similar and dissimilar metals at very high quality weld, low heat affected zone, absence of slag etc. Gas tungsten arc welding wildly uses a non electrode to produce the weld because it created a very high temperature to weld the metals. Weld zone is protected by a shielding gas (usually inert gas such as argon) from atmospheric air or gases and a filler material is normally used for fill the gap of metal [3]. The reported work have been described that there are many parameters that control the weld ability of dissimilar metals such as their crystal structure , chemical composition, solubility in the liquid and reading of filler metal in the weld pool area frequently leads to the creation of inter-metallic metallic phases are brittle and hard and affect the ductility of joint, mechanical strength of the joint and toughness.
inert gas welding is a joining process and it can be wildly used in modern industries for joining either similar or dissimilar metal Weldments. Tungsten inert gas welding is often known as gas tungsten arc welding (GTAW) .The advantages of gas welding like joining of similar and dissimilar metals at very high quality weld, low heat affected zone, absence of slag etc. Gas tungsten arc welding wildly uses a non-consumable tungsten electrode to produce the weld because it created a mperature to weld the metals. Weld zone is protected by a shielding gas (usually inert gas such as argon) from atmospheric air or gases and a filler material is normally used for fill the gap of metal [3].
International Journal of Trend in Scientific Research and Development (IJTSRD) ISSN: 2456 @ IJTSRD | Available Online @ www.ijtsrd.com

Experimental:
In this research the dissimilar metal welding between AISI 310 and AISI 316 L was carried out by using TIG welding process with two different filler metals. The base metal used for dissimilar welding were AISI 310 and AISI 316 L and thickness of base metals were 4 mm. AISI 316L and 90 S was used as filler metal. The chemical compositions of base metal and filler metals are shown in Tables 1 and 2, respectively  Metallurgical investigations of the joint were done after polishing the weld samples. The samples were prepared by first cutting in appropriate size by wire cut machine and then grinding using 80,120, 400, 800, 600, 1000, 1500 and 2000 grits of emery papers and final polishing is done by using 0.5μm diamond powder. Optical microstructure was measured along a straight line starting from first base metal, HAZ, weld metal, HAZ and ends at second base metal by an optical-microscope and a scanni microscope equipped with an energy dispersion X Ray spectrometer (SEM/EDS). And micro hardness of all three specimens is measure by micro hardness testing machine. The mechanical properties of the welded joint were analyzed by conducting various tests. The tensile test was performed at a crosshead speed of 3 mm/min. The shape of the specimens which were used for performing tensile tests was dumbled shape and the length was In this research the dissimilar metal welding between AISI 310 and AISI 316 L was carried out by using TIG welding process with two different filler metals. The base metal used for dissimilar welding were AISI of base metals were 4 mm. AISI 316L and 90 S was used as filler metal. The chemical compositions of base metal and filler metals are shown in Tables 1 and 2, respectively hemical Composition of Base Metal

Filler Metal
Metallurgical investigations of the joint were done after polishing the weld samples. The samples were prepared by first cutting in appropriate size by wire cut machine and then grinding using 80,120, 400, 800, s of emery papers and final polishing is done by using 0.5μm diamond powder. Optical microstructure was measured along a straight line starting from first base metal, HAZ, weld metal, HAZ and ends at second base metal by an microscope and a scanning electron microscope equipped with an energy dispersion X-Ray spectrometer (SEM/EDS). And micro hardness of all three specimens is measure by micro-vicker hardness testing machine. The mechanical properties of the welded joint were analyzed by conducting various tests. The tensile test was performed at a crosshead speed of 3 mm/min. The shape of the specimens which were used for performing tensile tests was dumbled shape and the length was 200mm and width was 20mm as shown in fig: 2. For microstructure observations, the welded samples were cut right angle to the welding direction from the welded joints and after cutting the samples in small pieces then polished and etched by using a kroll solution. Optical micro-scope was used to observe the microstructure of the weld interface. Scanning electron microscope (SEM) was used to observe the microstructure, element distribution and fracture analysis. For microstructure observations, the welded samples were cut right angle to the welding direction from the welded joints and after cutting the samples in small pieces then polished and etched by using a kroll scope was used to observe the microstructure of the weld interface. Scanning electron microscope (SEM) was used to observe the microstructure, element distribution and fracture SEM/EDS: Figure 5 shows an SEM (Scanning electron micro-scope) images at the joint interface of the sample 1 and 2 at magnification level and x35 respectively. The composition of Cr, Fe and Ni were observed in interface by EDS.
International Journal of Trend in Scientific Research and Development (IJTSRD) ISSN: 2456 @ IJTSRD | Available Online @ www.ijtsrd.com | Volume -2 | Issue -3 | Mar-Apr 2018 Table: 3. Shows comparison of micro-hardness of A tensile test is the most common type mechanical test we can perform to predict the ultimate tensile strength of specimen. A tensile test is fully standardized, simple and less expensive. By pulling on something, you will very quickly determine material will react to forces being applied in tension. By pulling material, you will find its strength along with how much it will elongate. One of the properties you can determine about a material is its ultimate tensile strength. This is the maximum load the specimen sustains during the test. The ultimate tensile strength may or may not equate to the strength at break. This all depends on what type of material you are testing brittle, ductile or a substance that even ocess involves placing the test specimen in the machine and applying Tensile test of the samples were done on universal testing machine and the ultimate tensile strength of 4.Ultimate tensile strength of samples. Ultimate tensile strength of all the samples is lies in Figure 5 shows an SEM (Scanning scope) images at the joint interface of the sample 1 and 2 at magnification level of x33, x33 and x35 respectively. The composition of Cr, Fe and