Effect Of Welding Parameters Research Articles

Statistical analysis of the effect of welding parameters on the tensile strength of titanium reinforced mild steel joints using taguchi’s DoE

Abstract Gas Metal Arc Welding (GMAW) is one of the most widely used metal fusion welding processes in the industry. This is largely due to its relatively high quality, ease of use, affordability and suitability for joining many metals including mild steel. By Incorporating Taguchi’s Design of Experiment to GMAW processes, high-quality response optimized welds can be obtained. The effect of welding parameters on the tensile strength of titanium-reinforced mild steel welds are investigated in this study. Using Taguchi’s L4 Orthogonal arrays for experimental design, GMAW was carried out on reinforced butt and lap welded mild steel. The parameters of interest were welding voltage, welding current and titanium powder reinforcement. Taguchi’s signal-to-noise ratios were calculated to obtain optimum welding parameters for tensile strength. Analysis of Variance (ANOVA) was used to determine any statistically significant welding parameter. The optimum parameters obtained for the reinforced butt welds were found to be 24 V, 130A and Ti 6–2–2–2–2 alloy. For the lap joints, the optimum parameters were found to be 26 V, 215A and Ti 6–2–2–2–2 alloy. However, ANOVA results indicate that none of the selected parameters were individually significant for both the butt and lap joints. This could be attributed to the small size of the orthogonal array used for this process of optimisation.

Effect of the welding parameters on the surface morphology of resistance spot welded AISI 304 stainless steel joints

Abstract Resistance spot welding is an extensively used production process in the industry. The joint strength of sheet metal parts bonded by resistance spot welding is expected to be sufficient. Furthermore, it is desirable that the appearance of the welding area be acceptable on visible surfaces. In regard to having an adequate surface appearance on the welded area, is necessary to remove the color changes on the unpainted surfaces and to eliminate the indentations caused by the welding pressure. In this study, an objective evaluation was performed using the color measurements of the test samples joined with resistance spot welding. The effects of welding parameters on surface appearance were investigated and the most suitable settings for the appearance of the welded surface were discussed.

Self-consumption friction plug spot welding of Ti–6Al–4V plates

In this work, a new technique of self-consumption friction plug spot welding (SFPSW) was introduced to spot welding of Ti–6Al–4V alloy sheets using a semi-consumable welding tool, and defect-free joints were successfully produced. The semi-consumable welding tool consists of a nickel-based superalloy shoulder and a titanium alloy plug. The spot welding parameters were discussed, and the effect of welding parameters on the microstructure and mechanical properties of the joints was investigated. The cross-section of the welding zone was divided into five regions: base metal (BM), heat-affected zone (HAZ), thermo-mechanically affected zone (TMAZ), stir zone (SZ), and filled zone (FZ). The final joint interface has a basket-weave structure. The maximum tensile-shear load of the joint was up to 69.5 kN and the hardness value of the welding region was lower than that of base metal. The failure mode of the tensile-shear test was a typical quasi-cleavage fracture.

Effect of process parameters on bead geometry, tensile and microstructural properties of double-sided butt submerged arc welding of SS 304 austenitic stainless steel

The purpose of this investigation is to study the effect of welding variables on bead geometry, fusion zone profile and tensile properties of double-sided submerged arc welding on SS 304 austenitic stainless steel. The individual effect of welding parameters, i.e., welding current, voltage and traverse speed, on bead geometry and tensile properties was investigated. Both microstructural and mechanical characterizations of the weldment were carried out in the present study. It was observed that the operating parameters have significant effect on bead geometry and tensile properties. The double-sided welding effectively enhanced the weld seam ductility. The percentage of elongation is improved by 19.48% to 50.2% for double-sided samples as compared to base material. A comparative study between single and double-sided butt welding was also carried out. For single-sided sample the percentage of elongation is lower than the base material. The percentage reduction in angular distortion of 55.17% is observed with double-sided weld sample as compared to single-sided weld sample.

Pinless friction stir spot welding of aluminium alloy with copper interlayer

Abstract Spot welding joints of Al-Mg-Si alloy (AA6061-T6) were produced with and without the addition of copper interlayer using pinless friction stir spot welding (P-FSSW). To investigate the effects of welding parameters on the metallurgical and mechanical properties of the weldment, various tool plunge depth and dwell time were used. Optical microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDS) have been used for microstructural characterisation.Meanwhile, the mechanical characterisation of the welded joints was evaluated by tensile-shear test. The experimental results showed that a larger bonding area and sound joint were achieved with the addition of Cu interlayer due to the improvement in thermal distribution. Also, an alloying reaction took place between the aluminium substrate and Cu interlayer during P-FSSW, forming intermetallic compounds layer in the interface through the diffusion process. The increasing of dwell time and plunge depth to some extent were beneficial to the formation of the joint and diffusion process, and thus increasing the tensile-shear load of the joints. The observed fracture mode of the joint was either completely shear off in the interface or complete nugget pullout.

Influence of welding parameters on microstructure and mechanical properties of electron beam welded Ti60 to GH3128 joint with a Cu interlayer

Effects of welding parameters on the microstructure and mechanical properties of Ti/Cu/Ni joint welded by electron beam were investigated. High welding heat input increased the melting quantity of Ti60 titanium alloy and promoted the formation of Ti–Cu intermetallic compounds (IMC) such as Ti2Cu and Ti3Cu4, increasing the brittleness of the joints. Low welding heat input was not conducive to the complete melting of the copper interlayer, and the unmelted copper reduced the performance of the joints. Under the optimal welding parameters, Ti–Ni IMCs in the weld would be replaced by (Cu, Ni) solid solutions ((Cu, Ni)ss). However, Ti–Cu IMC layers cannot be eliminated entirely by changing the welding parameters. The maximum tensile strength of the joints was 201 MPa. The fracture of the joints occurred at the Ti–Cu IMC layer, which was a typical brittle fracture.

Effect of Welding Parameter on the Corrosion Rate of Underwater Wet Welded SS400 Low Carbon Steel

This study aims to determine the effect of welding parameters on the corrosion rate of underwater wet welded SS400 low carbon steel. The underwater wet welding process was conducted using shielded metal arc welding (SMAW). Three welding electrodes, i.e., E7016, RB26 and RD26, were used in underwater wet welding performed with water depth variations 2.5 m, 5 m and 10 m. Welding current in the experiment was set to be 100 A and 110 A. After the welding stage, corrosion test was carried out on each joint in a 3.5%-NaCl solution using three-electrode polarization resistance methods. Corrosion testing results indicated that the lowest corrosion rate was found in underwater welding with current parameters of 100 A, 2.5-m depth and RB26 electrodes. The highest corrosion rate is obtained with the setting of underwater welding of 110-A current, 10-m depth and E7016 electrodes.

Effects of welding parameters on micro-junction structure and fracture behavior of refill friction stir spot welded joints for 2060 aluminum alloys

Due to different filling modes of the material in sleeve-affected zone (SAZ), probe-affected zone (PAZ), and thermo-mechanically affected zone (TMAZ), the micro-junction structure is formed at the bottom of the SAZ of the refill FSSW joint for 3.2-mm-thick 2060 aluminum alloys. The plasticized degree of the filling material and refilling time greatly affect the morphologies of micro-junction structure. Thus, the welding defects such as void with different sizes, kissing bond, and crack are easily formed in the micro-junction structure. Besides, the tensile-shear properties are related to the micro-junction structure and bonding strength of the lap interface. The increase of the plunge depth or rotation speed within a certain range enhances the flow of material in the stir zone and increases the atomic diffusion capacity of the lap interface, which is beneficial to increasing the tensile-shear load. The maximum tensile-shear load was obtained when the rotation speed of 2500 rpm and the plunge depth of 4 mm are used, and the tensile-shear specimen fractures along the bottom of the SAZ. Other fracture paths are also obtained under different welding parameters combinations, first along the lap interface, and second, not only along the lap interface but along the SAZ bottom.

Pengaruh Clamping Frame Kayu Meranti dan ASTM A36 pada Friction Spot Joining AL 1100 dan PVC

In this paper, the effect of welding parameters on the shear strength of Al-PVC hybrid structures was discussed. This Research developed welding parameters in the form of Plunge Depth, heating time, and clamping frame materials. By these different parameters would result in different shear strength of welded materials. Following optimization of the process, a detailed comparison of the properties and microstructures of two different materials (meranti wood and ASTM A36 Steel) would affect to different values of thermal conductivity. The Aluminum used was Al 1100, which was welded by using a friction stir spot welding method with Polyvinyl Chloride (PVC). In this study, by the different heating times, the shear test was carried out with the ASTM D3163 standard. In this study, it was found that the maximum temperature of Aluminum occurs during the 2 nd second of the welding process and then decreased in the 5 th second until 60 th second. However, the optimum shear strength found at 20 th second. Following heat transfer and degradation materials, the 2mm plunge depth has a higher temperature and higher shear strength than 1,5mm plunge depth. Differences in the response of the two depth were attributed to the difference in mechanical interlocking. This study found that the ASTM A36 clamping frame maximum shear load of 182.4 N is higher than meranti wood frame of 125.5 N. Differences in these value are attributed to the differences of the thermal conductivity, which meranti wood had a lower thermal conductivity than ASTM A36. These have findings significant implications for the commercial application of welding hybrid structures. The best way to take advantage of the benefit of AL-PVC Structure Hybrid for friction stir spot welding would appear to be 20 second heating time, 2mm plunge depth with ASTM clamping frame.

Investigation on welding distortion in stainless steel sheet using gas tungsten arc welding process

TIG welding has found wide applications in various industries for sheet metal joining process due to its simple process with high quality welds. However, it still experiences various form of defects to the weld components such as incomplete fusion, undercut, cracks and distortion which might affect production accuracy, appearance and strength of weld components. It is obvious that various welding parameters can affect the welding distortion. The present study attempts to investigate the effect of welding parameters namely welding current and diameter of filler rod on the distortion angle, tensile strength and change in microstructures. The experiment was performed on a closed butt joint type of welding using a commercial TIG welding machine. A full factorial experiment was utilized in the present study. A higher welding current produced more heat input into the weld zone thus resulting in a higher angular distortion. Similarly, a bigger diameter of filler rod produced more angular distortion attributed to the bigger size of weld bead. While, the tensile strength increased with an increase of welding current whereas, the filler rod diameters showed no clear and direct effect. Based on the microstructures of weld area, there were full penetration joints with no obvious defects such as hot cracking and porosities.

Porosity distribution and mechanical response of laser-MIG hybrid butt welded 6082-T6 aluminum alloy joint

6082-T6 aluminum alloy with thickness of 6 mm were welded by laser-MIG hybrid welding. The effects of welding parameters on the porosity distribution, the correlations between the porosity distribution and mechanical properties were comprehensively investigated. The porosities mainly appeared near the fusion line of the arc zone when the arc current larger than 140 A, and which mainly existed in the center of the laser zone with other unsuitable parameters. Adopting low welding speed and setting heat source distance as around 3 mm were beneficial for the reduction of the porosity rate. The laser power, defocus distance, fit-up gap and gas flow rate had less effects on the porosity distribution. The average tensile strength of the joints without porosities was 260 MPa, which decreased to 224 MPa and 202 MPa as the porosity rate increased to 5.1% and 8.9%. The tensile specimens fractured at the heat affected zone or in the weld center when the porosity rates less or greater than 3%, and the fracture feature was diverted from ductile fracture to ductile and brittle mixed mode as the porosity rate increasing. The fatigue strength reduced from 113 MPa to 56 MPa when the porosity rate increased from 0% to 8.9%, while the porosity position had little effect on it. The fracture initiated in the weld surface when the joints without porosity, and which initiated near the porosity when the porosities existed in the joint.

Effect of Weld Parameters on the Microstructure of Aluminum-Copper Joints Produced by Flash Welding

The effects of operational conditions on dissimilar Al-Cu flash welded joint quality have been studied using a series of industrial welding experiments. Macro- and microstructural analyses of dissimilar aluminum-copper joints produced by flash butt welding are performed in the present work. Various process conditions including standard and non-standard operational conditions were assessed during the welding experiments. Optical and scanning electron microscopy and electron dispersive x-ray spectroscopy are used to investigate and assess the metallurgical joints created through this process. For suboptimal process conditions, voids (5 mm wide, 1 mm deep) were observed at the joint interface. Some of the voids contained remnants of molten metal while some were empty. Al-Cu intermetallic compounds at the joint area were investigated, and their chemical compositions are determined. The profile of the joint interface was observed to be wavy which is attributed to the voids on the copper side and insufficient material flow of the copper during the upset. The effects of welding parameters on the waviness of the interfaces are investigated. The results show that the waviness of the interface increases with increasing the heat intensity (heat/joint area). No correlation was observed between the flashing speed and the waviness of the interfaces.

MAG Welding of Structures Used in Means of Transport and Made of Steel DOCOL 1200M

Steels of the DOCOL group, characterised by high tensile strength and yield point, play an important role in the manufacturing of means of transport. However, the above-named steels are difficult to weld and joints made in them do not guarantee comparable mechanical properties. The research work discussed in the article aimed to determine process parameters suitable for the welding of a moving platform made of steel DOCOL 1200M as well as to assess the effect of welding parameters on the quality of obtained joints. The tests also involved analysing the effect of shielding gases, preheating and interpass temperature on the quality of an 8 mm thick MAG welded moving platform structure.

EFFECTS OF WELDING CURRENT ON THE SHAPE AND MICROSTRUCTURE FORMATION OF THIN-WALLED LOW-CARBON PARTS BUILT BY WIRE ARC ADDITIVE MANUFACTURING

Wire arc additive manufacturing (WAAM) is nowadays gaining much attention from both the academic and industrial sectors for the manufacture of medium and large dimension metal parts because of its high deposition rate and low costs of equipment investment. In the literature, WAAM has been extensively investigated in terms of the shape and dimension accuracy of built parts. However, limited research has focused on the effects of welding parameters on the microstructural characteristics of parts manufactured by this process. In this paper, the effects of welding current in the WAAM process on the shape and the microstructure formation of built thin-walled low-carbon steel components were studied. For this purpose, the thin-walled low-carbon steel samples were built layer-by-layer on the substrates by using an industrial gas metal arc welding robot with different levels of welding current. The shape, microstructures and mechanical properties of built samples were then analyzed. The obtained results show that the welding current plays an important role in the shape stability, but does not significantly influence on the microstructure formation of built thin-walled samples. The increase of the welding current only leads to coarser grain size and resulting in decreasing the hardness of built materials in each zone of the built sample. The mechanical properties (hardness and tensile properties) of the WAAM-built thin-walled low-carbon steel parts are also comparable to those of wrought low-carbon steel, and to be adequate with real applications.

Effect of the welding parameters on the surface morphology of resistance spot welded AISI 304 stainless steel joints

Abstract Resistance spot welding is an extensively used production process in the industry. The joint strength of sheet metal parts bonded by resistance spot welding is expected to be sufficient. Furthermore, it is desirable that the appearance of the welding area be acceptable on visible surfaces. In regard to having an adequate surface appearance on the welded area, is necessary to remove the color changes on the unpainted surfaces and to eliminate the indentations caused by the welding pressure. In this study, an objective evaluation was performed using the color measurements of the test samples joined with resistance spot welding. The effects of welding parameters on surface appearance were investigated and the most suitable settings for the appearance of the welded surface were discussed.

Experimental study and taguchi optimization of process parameter on mechanical properties of A319 aluminum alloy using friction stir welding

The main objective of this abstract is to investigate the effect of welding parameters and the mechanical properties in the study of FSW. In this process, the mathematical model was developed by creating the Taguchi design methodology with three parameters, three levels, and 9 runs and it was also used to develop the relationship between those parameters. It can be produced and using a wide range of process parameters and its recommendation for producing the best joint tensile properties. Taguchi Method is used for the optimization of FSW process parameters for the joining of A319 Aluminum alloys. Taguchi method is signal to noise ratio (S/N) analysis that suggests the maximum tensile strength is reached when rotation, traverse speed, and tool pin diameter were chosen as 900 rpm, 40 mm/ min and 5.5 mm pin diameter respectively. ANOVA is used to find out the importance of the parameters. FSW can produce a satisfactory result of 141.05 MPa tensile strength and 112.04 MPa yield strength. FSW can weld A319 plates with a joint efficiency of around 75%.

CLADDING OF STAINLESS STEEL OVER MILD STEEL BY USING FLUX CORED ARC WELDING

Cladding is a process in which the corrosion resistance material is deposited over a low carbon steel plate to improve its desired properties. It finds application in repairing worn out parts for achieving good corrosion resistant surface. The project is carried out with an objective of studying the effect of weld parameters on mechanical properties including corrosion resistance. The weld parameters considered are welding speed, weld current and arc voltage. Stainless steel is found to have good corrosive resistance and depositing it on steel plate will ensure protection against corrosion. Stainless steel cladding is generally followed to attain better resistance towards corrosion in chemical, marine, and nuclear applications. The experiment is done using E309L flux cored Super stainless on Mild steel of standard IS 2062. The study reveals improved mechanical properties and better corrosion resistance.

Investigation of Microstructure, Mechanical Properties, and Numerical Modeling of Ti6Al4V Joints Produced by Friction Stir Spot Welding

In this work, lap-joined titanium alloy sheets have been successfully spot welded using friction stir spot welding (FSSW). Fully consolidated spot welds of thin Ti6Al4V sheets were obtained with a convex scrolled polycrystalline cubic boron nitride probe. The influence of processing parameters on FSSW was evaluated through a finite element analysis (FEA). Numerical results showed that von Mises stress and strain distributions were non-symmetric in the stir zone, whereas higher temperatures were observed in the region next to the tool pin. The welding microstructures showed different effects due to temperature gradients and material flow. The tool configuration played a significant role when determining the spot weld quality, since it directly influences the flow behavior of FSSW. It was observed that, in the stir zone, the microstructure suffered a transformation from α to β. The effect of welding parameters and the development of a FEA for the friction stir spot process were explored in the current investigation.

EFFECT OF ELECTRIC ARC WELDING ON IMPACT OF DIFFERENT MILD STEEL WELD GEOMETRIES

The effect of welding parameters (current, electrode diameter) on the impact of low carbon steel specimens was investigated in this work. Two different geometries namely square butt welded joint and double V welded joint were created. The welding operation was carried out at three different current for welding currents of 90, 110 and 130 amps and electrode diameters of 2.5, 3.2 and 4mm respectively. A Charpy impact testing machine was used to evaluate the impact of the welded samples. It was observed that a low current of 90 Amps for all the welding electrode diameters produced high impact values for both the welding geometries. Also, the 3.2 mm electrode diameter was found to be more suitable for welding the square butt and the double V geometry as it yielded higher impact values. Additionally, the double V geometry showed better performance when compared to the square butt geometry for all the combinations of welding currents and electrode diameters.

Weld Strength of Laser Welded SS316 and SS321

Nowadays, due to economic considerations, stainless steel is frequently used in dissimilar welds configurations– alloyed steel, carbon steel, copper, titanium. Current research in laser welding aims at joining a large category of structurally dissimilar materials, like copper, stainless steel or aluminum components. The weld quality of 10mm thick stainless steel grades of 316 and 321 laser welded in butt configuration is studied. SS321 is well known for its corrosion resistance property especially dissimilar metal corrosion ie., galvanic corrosion. SS316 provides high strength to weight ratio even at high temperature which makes its as a potential candidate for aerospace application. The joint quality is characterized in terms of hardness, microstructure and inspected using NDT. Scanning Electron Microscope and Optical Microscope were used to study the microstructure of welded specimen. The microhardness test is conducted on the weld joints to quantify the effect of weld parameters in mechanical strength of the joints. Radiography test was conducted to identify the defects in the specimen.