Mechanical Characterization of SA-508Gr3 and SS-304L Steel Weldments (original) (raw)
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IRJET-Evaluation of Hardness of Bimetallic Weld joint between SA-508Gr3 and SS-304L
Bimetallic Welds has its importance in the Pressurized Vessels used in Nuclear Power Plants which consists of pressurized water reactors (PWR) and steam generators in Boilers, where metals have to bear high temperature. The main focus of this work is to improve the mechanical properties of weld formed by joining the two dissimilar metals because failure of such metals at weld is very common in power plants and boilers where high temperature start-ups and shut- down are taken very frequently. In this work, dissimilar materials carbon steel SA 508 Gr3 and stainless steel type SS304 L was used. Buttering is considered for improving the properties, which is done with stainless steel (Grade-SS309L) and stainless steel (Grade-SS308L) as a filler material. Hardness and impact test were conducted to measure the micro hardness and toughness. The maximum hardness 37.5 and 27.5 were found in the weld joint for buttering and without buttering respectively. Key Words: Bimetallic Welding, SA-508Gr3, SS-304L, Toughness, Hardness.
Evaluation of Hardness of Bimetallic Weld joint between SA-508Gr3 and SS-304L
Bimetallic Welds has its importance in the Pressurized Vessels used in Nuclear Power Plants which consists of pressurized water reactors (PWR) and steam generators in Boilers, where metals have to bear high temperature. The main focus of this work is to improve the mechanical properties of weld formed by joining the two dissimilar metals because failure of such metals at weld is very common in power plants and boilers where high temperature start-ups and shutdown are taken very frequently. In this work, dissimilar materials carbon steel SA 508 Gr3 and stainless steel type SS304 L was used. Buttering is considered for improving the properties, which is done with stainless steel (Grade-SS309L) and stainless steel (Grade-SS308L) as a filler material. Hardness and impact test were conducted to measure the micro hardness and toughness. The maximum hardness 37.5 and 27.5 were found in the weld joint for buttering and without buttering respectively.
The International Journal of Advanced Culture Technology, 2015
The application of SS400 carbon steel and AISI430 ferritic stainless steel joint has been increased in industries because of the advantage of both metals was able to increase the service lifetime of the important structures. Therefore, a fusion welding process that could produce a sound weld and good joint properties should be optimized. This research is aimed to weld a butt joint of SS400 carbon steel and AISI430 ferritic stainless steel using Gas Metal Arc Welding (GMAW) welding process and to study the effects of welding parameters on joint properties. The experimental results were concluded as follows. The optimized welding parameter that produced the tensile strength of 448 MPa was the welding current of 110A, the welding speed of 400 mm/min and the mixed gas of 80%Ar + 20%CO 2. Increase of the welding current affected to increase and decrease the tensile strength of the joint, respectively. Lower welding current produced the incomplete bonding of the metals and indicated the low tensile strength. Microstructure investigation of the welded joint showed a columnar grain in the weld metal and a coarse grain in the heat affected zone (HAZ). The unknown hard precipitated phases were also found at the grain boundaries of the weld metal and HAZ. The hardness profile did not show the difference of the hardness on the joint that was welded by various welding currents but the hardness of the weld metal was higher than that of the other location.
Investigation on Property Relationship in Various Austenitic Stainless Steel 304L Welds
In the present work an investigation was made on property relationship of SS 304L austenitic stainless steel welds. Shielded metal arc welding (SMAW), gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) methods were used to make welds. Tensile test was used to measure the yield strength and ultimate tensile strength of the welds. Impact test was used to measure the toughness of the welds. Experimental results clearly revealed that these properties of GTAW was superior compared to the other two welds. This was due to more weld penetration at lower heat input into the base metal. The disadvantage of SMAW and GMAW is that the slag must be chipped off of the weld after it cools and can sometimes infiltrate the weld causing weakness.
IOP Conference Series: Materials Science and Engineering
In the present study, an attempt has been made to weld dissimilar alloys of 5mm thick plates i.e., austenitic stainless steel (316L) and duplex stainless steel (2205) and compared with that of similar welds. Welds are made with conventional gas tungsten arc welding (GTAW) process with two different filler wires namely i.e., 309L and 2209. Welds were characterized using optical microscopy to observe the microstructural changes and correlate with mechanical properties using hardness, tensile and impact testing. Potentio-dynamic polarization studies were carried out to observe the pitting corrosion behaviour in different regions of the welds. Results of the present study established that change in filler wire composition resulted in microstructural variation in all the welds with different morphology of ferrite and austenite. Welds made with 2209 filler showed plate like widmanstatten austenite (WA) nucleated at grain boundaries. Compared to similar stainless steel welds inferior mechanical properties was observed in dissimilar stainless steel welds. Pitting corrosion resistance is observed to be low for dissimilar stainless steel welds when compared to similar stainless steel welds. Overall study showed that similar duplex stainless steel welds having favorable microstructure and resulted in better mechanical properties and corrosion resistance. Relatively dissimilar stainless steel welds made with 309L filler obtained optimum combination of mechanical properties and pitting corrosion resistance when compared to 2209 filler and is recommended for industrial practice.
_____________________________________________________________________________________________________________ 1. Introduction Gas tungsten arc welding (GTAW) or tungsten inert gas (TIG) is an arc welding process that creates an arc between a non-consumable tungsten electrode and a welded workpiece. TIG is commonly used in railway vehicle construction, automotive and chemical industries. Stainless steel is used as an important material in the industry due to its excellent corrosion resistance. TIG is one of the welding processes and is commonly used to weld uniform and different stainless steel joints. It has been observed that most of the work is done on stainless steel, which is the most commonly used stainless steel in the world. Key areas of research are weld characterization, dissimilar metal welding, parameter optimization, process modeling, fault analysis and automation of the TIG welding process. GTAW welding is an arc welding process in which fusion energy is generated by burning between a workpiece and a tungsten electrode by an electric arc. The electrode and the weld pool are protected from the harmful effects of the atmosphere by an inert protective gas during the welding process. The shield passes through the gas nozzle to the gas weld zone where it replaces the atmosphere. TIG welding differs from other arc welding processes in that the electrodes are not used like electrodes like other processes such as MIG / MAG and MM. Stainless steel is widely used in the manufacture of sheet metal, especially in automotive, chemical and railway passenger cars, mainly due to its corrosion resistance and weight ratio. Stainless steel is a generic name that covers a group of metal alloys with a chromium content of more than 10.5% and a maximum carbon content of 1.2% (according to European standard N10088). It is usually include other elements such as nickel and molybdenum. Failure analysis and literature investigations of diffusion welded joints have shown that a large number of failures have occurred in the heat affected zone (HAZ) [1]. They studied dissimilar metal welds made of low alloy steel, Inconel 82/182, and stainless steel prepared using gas tungsten arc welding and shielded metal arc welding. The microstructure was observed using an optical and electron microscope. A specific dendritic structure was observed The dissimilar weld joint is considered as one of the most commonly used fabrication methods in now a day. The most popular welding for dissimilar alloy is tungsten inert gas welding (TIG) in which inert and active gases are used. In this work SS202 and SS304 are used for welding. SS 202 has almost similar mechanical properties as compared to SS304 grade, but its ability to resist corrosion is somewhat less as compared to SS304 grade in chloride environment. These materials and their welding is used in nuclear reactor and pressure vessel where high temperature is used. The object of this paper is to investigate the mechanical properties and microstructure analysis of welded joint between SS202 and SS304 with two different filler metal SS308L and SS316L by tungsten inert gas welding. Higher tensile strength was achieved with filler rod SS308L. The analysis confirms the well mixing of stainless steel and mild steel with filler rods inside the weld pool. The mechanical properties in terms of ultimate tensile strength found to be high as 488.61N/mm 2 with filler rod SS308L and micro hardness value at the center of the welded zone was found maximum (272.2 HV) with filler material SS308L, the fracture of the tensile test specimen were obtained outside and at the weldment of the weld zone.
Materials Today: Proceedings, 2020
In this study of examination, the mechanical properties of AISI 304 stainless steel and copper fabricated by gas tungsten arc welding process (GTAW) are evaluated. Dissimilar material welding of AISI 304 stainless steel and copper are chosen in the industry because of their high tensile strength, hardness, good corrosion resistance and high electrical or thermal conductivity. The copper is difficult to welding because of high thermal conductivity which in turn tends to dissipate heat rapidly away from the weld leading to difficulties in reaching the melting temperature. In addition, high thermal expansion meaning that distortion can occur during welding. Due to the differences in material properties, there is uneven partitioning of the heat at the joint interface in dissimilar welding. To compensate for heat loss at the interface between these weld pads the heat source or welding torch was traversed at an offsetting distance toward copper. The purpose of this study is to evaluate the mechanical properties of the dissimilar weldment using gas tungsten arc welding (GTAW) for AISI 304 SS and copper with 1.25 mm offsetting distance. To reveal the effectiveness of the proposed scheme the mechanical properties in terms of microhardness and tensile strength of weldment are evaluated for the weldment viz-a-viz copper.
Metals, 2017
UNS S32205 duplex stainless steel plates with a thickness of 3 mm are arc stud welded by M8 × 40 mm AISI 304 austenitic stainless steel studs with constant stud lifts in order to investigate the effects of welding arc voltages on mechanical and microstructural behaviors of the joints. As the welding arc voltage increases starting from 140 V, the tensile strength of the weldment also increases but the higher arc values results in more spatters around the weld seam up to 180 V. Conversely, the lower arc voltages causes poor tensile strength values to weldments. Tensile tests proved that all of the samples are split from each other in the welding zone but deformation occurs in duplex plates during the tensile testing of weldments so that the elongation values are not practically notable. The satisfactory tensile strength and bending values are determined by applying 180 volts of welding arc voltage according to ISO 14555 standard. Peak values of micro hardness occurred in weld metal most probably as a consequence of increasing heat input decreasing the delta ferrite ratios. As the arc voltage increases, the width of the heat affected zone increases. Coarsening of delta-ferrite and austenite grains was observed in the weld metal peak temperature zone but it especially becomes visible closer to the duplex side in all samples. The large voids and unwelded zones up to approximately 1 mm by length are observed by macro-structure inspections. Besides visual tests and micro-structural surveys; bending and microhardness tests with radiographic inspection were applied to samples for maintaining the correct welding parameters in obtaining well-qualified weldments of these two distinct groups of stainless steel materials.
Effect of Gas Tungsten Arc Welded 308 and 409 Stainless Steels on Their Mechanical Properties
2015
Stainless steels (SS) in automobile sector were previously incorporated mainly due to their decorative applications. Nowadays, their functional and specific characteristics make them more required and employed in this sector. Especially attention from automotive manufacturers has been paid in order to improve the engine efficiency and reduce weight of the vehicle, stainless steels result to be enabled due to their high strength mechanical characteristics, energy absorption capability, fatigue and corrosion resistance; besides their ductility which is traduced to an easy manufacturability. When welding is applied some of their characteristics may be affected and could decrease their mechanical properties. In attempt to avoid these circumstances, welding experimental practices must be carried out. In this study plates of 308 austenitic and 409 ferritic stainless steels were welded by Gas Tungsten Arc Welding process with different current values in order to get their mechanical proper...