Filler Rod Research Articles

Weld bead temperature and residual stresses evaluations in multipass dissimilar INCONEL625 and SS316L by GTAW using IR thermography and x-ray diffraction techniques

Thick plates of SS to Inconel are used in nuclear reactors to withstand high temperatures and pressures. This study is to evaluate the GTAW joining of SS316L to Inconel625 to evaluate the weldability; the temperature distribution in the longitudinal and transverse directions, resulting in distortions and the induced residual stresses. To obtain real-time temperature images Infrared thermography measurements were made. Similar welding joints of SS to SS and Inconel to Inconel were used as a reference for comparison with the dissimilar welding parts in this evaluation. Compatible Filler rods were selected: SS316 filler rod was used for welding of SS316L samples and ERNiCrMo-3 was used when a part is IN625. This study reports the temperature distribution for a SS to Inconel weld process and the resulting distortion and residual stresses were within the acceptable limits.

Tensile properties and strengthening effects of Al 3003 alloy weldment reinforced with TiO2 nanoparticles

This paper examines the significance of strengthening mechanisms in the fabricated Al 3003 nanocomposite weldment using accumulative roll bonded (ARB) Al 1100 – TiO2 filler rod. The wt. % of titanium oxide (TiO2) content is varied as 0, 0.75, 1.5, 2.25 and 3 to the total weight of the weld zone. The weld possesses an ultimate tensile strength of 249 ± 04 MPa in 3% reinforced whereas 137 ± 04 MPa in unreinforced condition. The results obtained from the tensile test were cross checked with the characterization studies such as X ray line profile analysis (XRD), Field emission scanning electron microscopic analysis (FESEM), Transmission electron microscopic analysis (TEM), Electron backscattered diffraction analysis (EBSD) and Energy dispersive x-ray spectroscopic analysis (EDS). The tensile test results reveal that Al – 3 wt% TiO2 nanocomposite weld exhibits higher strength which is not only due to drop in grain size but also due to mechanisms such as grain refinement strengthening, Orowan strengthening and thermal expansion coefficient mismatch strengthening and occurred incommensurate with the progressive addition of TiO2 nanoparticles in the weldment. However, it has been found that the mechanism due to Orowan strengthening has played a significant and greater role for the overall strength of the weldment.

A study on the effect of stress relief heat treatment on the microstructure and mechanical properties of dissimilar GTAW weld joints of Inconel 625 and A106 carbon steel

In this study, the effect of stress relief heat treatment at different temperatures (900 °C, 1040 °C, and 1200 °C) on the mechanical properties and microstructure of Inconel 625 and A106 GTAW weld joint (using ER-625 as filler rod) has been investigated. The results showed that bainite phase was formed at the HAZ of A106 alloy which resulted in the brittleness of the alloy and hardness increase in the non-heat treated sample (187 and 210 HV at HAZ of A106 and Inconel, respectively). By applying the stress relief process, bainite phase was omitted from the microstructure and ferrite-pearlite structure was formed. By increasing the process temperature to 1200 °C, the austenitic grain boundaries appeared in the microstructure. EDS analysis approved the presence of molybdenum and niobium rich complex carbides in the welding metal microstructure. The results of tensile test also showed that without stress relief process, the sample ductility decreased by ∼27%. By applying the stress relief process, the ductility of samples obviously improved and the sample which was stress relieved at 1040 °C showed the best tensile properties (UTS of ∼493 MPa and ductility of ∼29%). By increasing the stress-relief temperature to 1200 °C, the strength (UTS of ∼443 MPa) and hardness of the sample decreased due to the growth of the grain size.

Simulation Study for TIG Welding of MONEL 400 and AISI 304

Objectives: ANSYS software has been used to predict temperature, stress, and heat flux distributions for dissimilar welding of MONEL 400 and AISI 304. Methods/Statistical Analysis: A total of twenty seven experiments have been performed for welding of MONEL 400 alloy and AISI 304 by using TIG welding process to find out the best possible welding parameters. The experiments conducted have been divided into three groups. In the first stage, second stage and third stage of experiments was conducted to study the welding process with AISI 304 filler rod, AISI 316 filler rod and MONEL 400 filler rod respectively. Findings: The developed stress is smaller at 350 amp current, AISI 304 filler rod, and 3.6 mm/s welding speed, which is noted as 0.31 × 10-15 MPa. The optimum TIG welding parameter for stress was obtained as 150 amp current, AISI 304 filler rod, and 3.6 mm/s welding speed. The mean value of generated temperature is higher at 350 amp current, AISI 316 filler rod, and 5.5 mm/s welding speed, which is observed as 75671°C. The optimum TIG welding parameters are 350 amp input current, AISI 316 filler electrode, and 3.6 mm/s welding speed for developed temperature. The optimum TIG welding parameter for heat flux was obtained as 350 amp current, MONEL 400 filler rod, and 5.5 mm/s welding speed. Application/Improvements: Dissimilar metal joints between MONEL 400 and AISI 304 are widely used in various applications fields like heat exchanger, chemical processing equipment etc. Keywords: AISI 304, ANSYS Software, Dissimilar Metal Weld, MONEL 400 Alloy, TIG welding, Welding Simulation

PENGARUH KUAT ARUS PADA PENGELASAN PADUAN ALUMINIUM 6061 DENGAN MENGGUNAKAN METODE LAS TIG TERHADAP KEKERASAN DAN STRUKTUR MIKRO

<em>The objective of research was to find out the effect of current on microstructure and hardness value in Aluminium Alloy 6061 before (raw material) and after welding using Tungsten Inert Gas (TIG) welding method with filler rod ER4043. This research uses experiment methods. Technique of analyzing data used was a descriptive comparative research. The instruments used for testing microstructure and hardness were Olympus Metallurgical Microscope and Vikers Hardness Tester. Base on the result of research, it could be concluded that the result of microstructure testing showed the reduced Mg<sub>2</sub>Si phase width after welding. In raw material, the Mg<sub>2</sub>Si phase seemed to diffuse surrounding the α-Al phase surface, but the result of welding using TIG welding method with current of I00 A, 110 A, and 115A showed that Mg<sub>2</sub>Si phase reduced in each specimen, so that α-Al phase was very dominant. The hardness value of hardness result showed the different hardness level. The specimen with current of 110A had higher hardness level of 65.4 VHN than the specimen with current of 100 A (55.7 VHN) and 115 A (55.9 VHN). The result of hardness testing on raw material was 120.4 VHN. This research showed that the welding using varying current changed microstructure and affected the hardness value of Aluminum Alloy 6061.</em>

Monitoring of Welding Process Parameters in Gas Tungsten Arc Welding of Carbon Steel Weldments

Results of present study show the possibilities to monitor and control the automatic gas tungsten arc welding process using additional filler rod, and investigate the evolution of microstructure and the mechanical characteristics of carbon steel weldments joint under the different welding parameters: welding current, arc voltage, and travel speed. Three types of weldments were produced and tested: build-up welds, U-grooved samples, and butt welds. Penetration and depth of heat affected zone in all types of welds are influenced especially by the welding current. Dendrite structure formed after welding gives a good indication of the thermodynamic processes during liquid metal solidification, welds are free from defects. The welded joints showed that crystal orientation and shape in the weld zone depend on thermodynamic processes during solidification and welding mode. The frequency and size of the successive droplets of the molten metal from the filler rod has been registered by piezoelectric sensor and due to the collected data the welding parameters and herewith the geometry and structure of heat affected zone and weld bead have been controlled. DOI: http://dx.doi.org/10.5755/j01.mech.25.1.22158

Influence of filler metals and PWHT regime on the microstructure and mechanical property relationships of CSEF steels dissimilar welded joints

The nuclear grade modified 9Cr1Mo (P91) and 9Cr-0.5Mo-1.8WVNb (P92) are commonly used material for power plant components operating in the temperature range of 600–650 °C. For such steels, the creep strength at the elevated operating temperature is the prime criteria. However, microstructure stability and notch toughness also play an important role, especially for the welded joints to meet the pressure test at room temperature. The room temperature mechanical properties of the welded joint are strongly influenced by the welding process, filler composition, composition of the base plate and heat treatment performed after the welding. In present work, P91 and P92 dissimilar multi-pass welded joints have been produced using the different filler rod. The microstructure of the welded joint has been studied for the different filler composition in various heat treatment condition. The room temperature Charpy impact toughness and tensile properties for the different welded joints (different filler) have been also studied and related with the microstructure of the welded joint. From the results, it has been concluded that a higher amount of ferrite stabilizer in P92 filler promotes the formation of the δ ferrite in the weld fusion zone.

Nanoparticle-enabled phase control for arc welding of unweldable aluminum alloy 7075

Lightweight materials are of paramount importance to reduce energy consumption and emissions in today’s society. For materials to qualify for widespread use in lightweight structural assembly, they must be weldable or joinable, which has been a long-standing issue for high strength aluminum alloys, such as 7075 (AA7075) due to their hot crack susceptibility during fusion welding. Here, we show that AA7075 can be safely arc welded without hot cracks by introducing nanoparticle-enabled phase control during welding. Joints welded with an AA7075 filler rod containing TiC nanoparticles not only exhibit fine globular grains and a modified secondary phase, both which intrinsically eliminate the materials hot crack susceptibility, but moreover show exceptional tensile strength in both as-welded and post-weld heat-treated conditions. This rather simple twist to the filler material of a fusion weld could be generally applied to a wide range of hot crack susceptible materials.

Evaluation of mechanical properties for TIG welding aspects of SS 310 and MS materials

Abstract Tungsten inert gas welding (TIG) is being extensively used as a crucial process in the modern automotive, aerospace, manufacturing and electronic industries as it can produce high quality welds with an appreciable accuracy. Quality of the weld and joint efficiency is the most obligatory requirement. Present work focused on evaluating the mechanical properties for TIG welding aspects of SS 310 and MS materials. An attempt has been made to investigate the influence of various parameters namely welding current, diameter of filler rod and gas flow rate on the responses such as tensile strength, percentage elongation and Rockwell hardness. Welding is performed to join 1.5 mm thick SS 310 and MS plates which were then made to ASTM standard tensile specimens to carry out the tensile test. The mechanical strength is also evaluated using Rockwell hardness test. The results revealed that it has a maximum tensile strength of 424.312 Mpa welded with 60 Amps and having a gas flow rate of 6 Lit/min by employing a filler rod of diameter 2 mm. Moreover, the maximum hardness value of 61 HRB was reported with the sample welded with 40 Amps & 5 Lit/min of gas flow rate by using a 1.5 mm diameter filler rod.

Evaluation of mechanical properties and micro structural charecterization of dissimilar TIG welded AISI 316L and AISI 430 plates using ER310 and ER2594 filler

In the present evaluation, We have made an attempt has to determine the weld characteristics of AISI 316 L (Low carbon steel) and AISI 430 by TIG (tungsten inert gas welding) Using ER310 and ER2594 as filler metals. The micro structural analysis of the welded region and the Heat Affected Zone (HAZ) has be examined with the help of optical microscope which helps to find the formation of unmixed zones at the HAZ. Tensile and Impact tests are carried out to find the material’s fracture properties on the weldments. This Evaluation will be useful for studying the structural –property relationships of dissimilar weldments using different filler rods.

Experimental Investigation of Corten A588 Filler Rod for Welding Weathering Steel

Abstract This analysis lays emphasis on finding a suitable substitute filler rod for welding weathering steel, such as to eliminate the risk of corrosion. The commonly used filler rod for welding weathering steel is ER70S-6 which is not immune to atmospheric corrosion under wetter conditions and in the presence of stagnant water. Under wetter conditions the ER70S-6 develops more rust by the formation of non-protective rust layers. For the improvement of mechanical, metallurgical and corrosion properties of the weld the parent metal is used as the filler material for welding the weathering steel. The filler wires are cut from the parent material as strips of wire sized 1.2mm. The welded joints are made between two weathering steel of dimensions 150 x150mm with a gap of 3mm between the plates. The Shielding gas used for GTAW welding of weathering steel is 100% Argon. The welds are then cut accordingly for tensile and impact testing using water jet cutting process. The test reviled the best suitable substitute filler rod for the commonly used ER70S-6.The findings are complied according to the mechanical properties found in the welds.

Microstructural and mechanical properties of dissimilar Al-Ti joints prepared by GTAW welding-brazing

Joining of light metals and alloys including Al-Ti is of great interest of many producers particularly from automotive and aerospace industries. In this paper, conventional gas tungsten arc welding-brazing method was applied to join 2 mm thick plates of wrought AA5083-H111 aluminium alloy with commercially pure titanium Grade 2 using ER4043 filler rod. Butt type of joints with single- and double-square-groove welds were produced using various welding currents. Mechanical properties of prepared welded-brazed joints were evaluated by tensile tests and microhardness measurements. Microstructural analyses were carried out using light microscopy. The weld zones and Al-Ti interfaces were observed by scanning electron microscope. EDX microanalysis was used to identify variations in chemical composition across the welded-brazed joint interface. Finally, the analysis of the influence of welding parameters on the mechanical properties and dimensions of the fusion zone was accomplished.

Improvement of materials for gas welding of cast iron

The aim of the study is to create a bar for gas welding of cast iron parts, with improved mechanical characteristics and lower hardness of the weld metal.A disadvantage of the known welding rods is the high hardness and low mechanical properties of the weld metal. This does not allow the use of the mentioned filler rods for welding critical structures and surfacing of parts to be machined in industrial volumes.As a filler material in gas and electric arc welding of cast iron, rods with a diameter of 8-10 mm from cast iron of grade A or B according to GOST 2671-80 were used. As a flux in gas welding, we used a technical drill according to GOST 8429-77, calcined at a temperature of 300350 ° C for 2 hours.Yttrium and erbium were used as an alloying and rare-earth metals additives in iron bars.The welding-technological properties of the investigated rod compositions were checked during gas (acetylene-oxygen) and electric arc welding of high-strength cast iron of grade VCh 40.Based on the tests of the welding and technological properties of the rods under study, it was determined that rod No. 2 is optimal, which ensures good wettability of the weld pool with molten metal. Slags are fusible and do not impede the conduct of the welding process for cutting large volumes. No weld defects.The structure of the deposited metal on the surface of the weld at a depth of 1.5-2 mm is pearlitic with small areas of austenite of dendritic orientation. Further along the height of the weld to the fusion line, perlite prevails in the structure. The inclusion of ferrite and cementite are single. Spherical graphite of medium size, slightly smaller than in the base metal.The hardness in this zone is 220-229 HB and allows easy machining of welds with conventional metal cutting tools.

Influence of MIG Welding Process Parameters on Tensile Properties of Mild Steel.

Metal Inert Gas welding (MIG) is a widely used welding method for mild steel (low carbon steel) in industry due to its high weld quality, good penetration and comparatively low investment. It is an arc welding process wherein coalescence is produced by heating the job with an electrical arc struck between a filler rod and the job. A Shielding gas (argon, carbon dioxide) is used to avoid atmospheric contamination of the molten weld pool. A filler material is added for joining the work piece by MIG welding. Many researchers investigated on different welding process parameters on mechanical & microstructural characteristics. Some researchers used the welding speed, welding current welding voltage, number of welding passes & work peace thickness for stainless steel, naval grade steel & aluminum. But the shielding gas flow rate & gas mixture also important factor which affects mechanical properties of mild steel. For this study, process parameters such as welding current, gas flow rate and gas combination used in the range 170-210A, 13-17 Lit/min & 0-100 % of CO2 respectively. The material used E-250 grade mild steel with 12 mm thickness. The effect of the welding parameter is investigated by designing the experiments using central composite matrix. Using the data generated by the experimentation, an empirical relation is obtained for tensile strength. The optimum value of tensile strength 356 N/mm2 is observed at 190A welding current, 15 Lit/min gas flow rate & 50% CO2+50% Argon gas combination.Index Terms—Co2 Welding, v-butt Welds, welding current, gas flow rate, Gas combination, Tensile strength.

Optimization of weld strength properties of tungsten inert gas mild steel welds using the response surface methodology

The rise in the failure of mechanical components, some of which are attributable to poor weld joints has given rise to research study on the optimization of weld joint strengths. The quality of welds is highly dependent on the right combination of input process parameters. Irrespective of the welding process, the need for the right combination of input process parameters cannot be over emphasized. To achieve a desired weld quality, the weld features such bead geometry and the mechanical properties were examined and related to the weld input parameters. The Response Surface Methodology (RSM) was used to predict and optimize the weld strength properties (tensile strength and hardness) of a Gas Tungsten Arc Welded 10mm thick mild steel plate. Model adequacy checks, was done using analysis of variance (ANOVA) and found to be adequate. The ANOVA showed that current and gas flow rate had the most significant effect on the tensile strength, but on the Hardness, the gas flow rate and filler rod had the most significant effect. The model F-value of 12.69 at a P value of 0.0001 for the tensile strength and F-value of 8.51 at a P value of 0.0001 for the hardness, showed the significance of the model employed. The optimal tensile strength of 497.555N/mm 2 and Hardness of 192.556BHN was observed at a current of 170.12 amp, voltage of 19.84 volt, gas flow rate of 23.92 l/min and filler rod diameter of 2.4mm. Keywords: welding, gas tungten arc welding, tensile strength, hardness, response surface methodology

Modeling performance of response surface methodology and artificial neural network

In recent years, response surface methodology (RSM) which is a statistical technique and artificial neural network (ANN) a soft computing technique have been highly used for modelling, simulation and optimization of several physical processes in engineering. Both RSM and ANN strategies have particular computational properties that makes them suitable for making predictions, but differ in their extrapolation and interpolation capabilities on complex non-linear processes, and thus potentially conflict in their predictive accuracy. This study models and compares the capabilities of RSM and ANN in predicting the tensile strength of a 6 mm thick mild steel gas tungsten arc welded plate based on the effects of input variables such as weld current, weld speed, gas flow rate and filler rod. The RSM and ANN based models for prediction were compared using the coefficient of determination criteria. With a higher value of 0.836, the ANN model proved to be a better modeling technique than the RSM model. Keywords: Soft Computing Techniques, Response Surface Method, Artificial Neural Network

Investigation of thermal effects on mechanical properties of 9Cr-1Mo to 9Cr-1Mo welded joints for high-temperature applications

Modified 9CR-1MO usage has been highly increased in recent years mainly under high-temperature application. This paper focusses on microstructure without post heat treatment and hardness, stress analysis of weld zone, heat affected zone and parent metal with and without post heat treatment. Here, among many suitable welding processes, we have been chosen Tungsten Inert Gas Welding with an appropriate filler rod ER308L.The post heat treatment is been carried out by an annealing process. The study of microstructure for 9cr-1mo steel mainly describes size and shape of grains by the Scanning Electronic Microscope, micro, and macro structure examination. The tensile and hardness strength of the 9cr-1mo steel has been determined by using suitable equipment throughout the base metal and weld zone. The microstructure is uniform and free from a dendritic pattern, the ductility of material more after annealing and the hardness of material become uniform overall except in HAZ.

Challenges in Fusion Welding of Al alloy for Body in White

Since the beginning of 21st century automobile industries are under great pressure to fulfill environmental regulations as well as user driven strict requirements such as low cost, safety, exhaust emissions, fuel efficiency, drivability, comfort and larger interior space. One of the options to address few of these challenges is reducing fuel consumption and so, it is now crucial for all the automobile manufacturers to get breakthrough in this direction. Various measures in engine modifications and hybrid systems are developed to reduce fuel consumption. However, main thrust area is automotive weight reduction, which is regarded as one of the most effective means for decreasing fuel consumption by replacing steel with aluminum. At present aluminum weight per vehicle is around 180 Kg/vehicle which will be increased to 250 Kg./vehicle by 2025. Joining of aluminum and repair of the aluminum in automobile body panels is still remain big challenge because of inherent properties of aluminum like low melting point, high thermal conductivity, high solubility of hydrogen, oxide formation and high solidification shrinkage. Aluminum is not forgiving material like still and produces several defects during welding of aluminum alloy. Hot tears, solidifying cracks, porosity, distortion and melt through are commonly observed in weld bead. Such defects drastically reduce fatigue strength and mechanical properties of aluminum alloy plates. These defects can be tackled by developing best practices in fusion welding. Especially in MIG welding, correct filler rod selection, reduced heat input, inert gas selection, welding techniques etc... can provide better quality weld beads in aluminum.

Increasing the strength of the deposits of titanium alloys using rods process by microarc oxidation

Deposition of a layer of a very hard metal on the surface of components is an efficient method of increasing the service life of structures made of titanium alloys and working in the sea or other corrosive media in abrasion conditions. The material for the surfacing wire is in most cases PT-7 M alloy enriched with oxygen as a result of thermal oxidation. The method studied, to replace thermal oxidation – microarc oxidation, is based on anodizing in electrolyte solutions of high potentials causing microplasma breakdown on the anode. The experiments confirm the promising nature of using microarc oxidation. The metal deposited by argon-arc non-consumable electrode welding with filler rods made of VT6sv alloy was treated by microarc oxidation, and the structure, quality and hardness satisfy the technical requirements. The application of microarc oxidation in contrast to thermal oxidation does not increase the hydrogen content of the wire so that it is not necessary to carry out vacuum degassing together with quenching in water nor subsequent mechanical dressing, and productivity is higher.

Si-bronze to 304 stainless steel GTA weld fusion zone microstructure and mechanical properties

Si-bronze and 304 stainless steel were joined using gas tungsten arc (GTA) welding with two different welding (filler) rods matching the base metals. Cross-sections of the welds were analyzed using light optical microscopy (LOM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and hardness testing. Mechanical testing was performed for welds from each of the two filler metals using cross-weld tensile bars. For (1) the Si-bronze filler weld, partial mixing resulted in (a) copper-based regions with enhanced hardness due to iron-based islands and (b) iron-based regions with elevated hardness due to Si enrichment. Joint strength was ~ 90% that of the base Si-bronze strength of 340MPa, and elongation was ~ 48%, as compared to the base Si-bronze elongation of 55%. For (2) the stainless steel filler rod (a) primary austenite solidification and (b) micro-fissures were identified in the fusion zone. Thermodynamics calculation software was used to model solidification mode, demonstrating that the Cu (contributed by the Si-bronze) stabilized primary austenite solidification, which led to solidification micro-cracking or micro-fissuring. Micro-fissuring caused low ductility in the transverse weld tensile specimens. Fractography was performed to characterize the fracture mechanisms. For the stainless filler weld, a Cu film formed in interdendritic spaces between primary austenite grains.