GMAW Welding Research Articles

Microstructure impact of CNT addition to 304 stainless steels robotic GMAW welds

Microstructure impact of CNT addition to 304 stainless steels robotic GMAW welds

Fillet weld strength analysis for cantilever loading: an investigation of single-sided fillet weld strength in bending applications

Theoretical calculations for assessing the strength of a welded connection in design rely on two parameters: the tensile strength of the weld filler metal and the effective area. It is important to note that the type of load applied can significantly affect the theoretical strength of the weld. According to the AWS Structural Welding Code D1.1, when the load is applied parallel to the weld in a welded member, a reduction of 70% is recommended. This remaining factor of 0.30 has been determined through well-accepted tests to provide factors of safety between 2.2 for shearing forces parallel to the longitudinal axis of the weld and 4.6 for forces normal to the axis under service loading. When a load is applied perpendicular to the weld in a welded member, the entire value of the tensile strength of the weld filler metal is used to calculate the strength. However, there are no similar considerations for a load applied in a bending configuration. While it is not recommended for structural design, fillet welded members can experience loading that causes material deflection, resulting in a bending scenario. This is particularly relevant in repairs. The configuration of a cantilevered beam creates a different loading scenario with additional stresses on the weld, which differ from those of a perpendicular or parallel load. This research experiment was conducted to initially understand and analyze the strength of a GMAW weld under cantilevered bending and to derive a mathematical equation that provides a factor of safety in the range of 2.2-4.6, similar to the previous findings.

Effect of Corrosion and Post-Weld Treatment on the Fatigue Behavior of Multipass Robot GMAW Welds of S700MC Steel

High-strength steel is a candidate material for offshore structures, which are currently being constructed with regular-strength steel. These structures are constantly exposed to harsh environmental conditions and experience cyclic loadings, which can lead to premature failure due to the synergistic effects of corrosion and fatigue. In this regard, the current study aims to investigate the effects of corrosion and High-Frequency Mechanical Impact (HFMI) treatment on the fatigue behavior of welded joints made of S700MC steel. Multipass butt-welded joints were fabricated via the Robot GMAW method at an optimally selected heat input of 0.7405 kJ/mm. The microstructure of the weldments was studied using light optical microscopy. Tensile and Vickers microhardness tests were performed to evaluate the mechanical properties of the welded joints. To simulate marine environment corrosion in the laboratory, the as-welded samples were exposed to salt fog spray for 720 h. Subsequently, specimens were subjected to cyclic loading to evaluate their fatigue strength, while SEM and stereomicroscopy were used to analyze the fractured surfaces, providing a comprehensive understanding of the fracture mode. The findings suggest that although corrosion led to increased surface roughness and the formation of corrosion pits, its influence on the fatigue behavior of the weldments might be less significant compared to other geometrical factors, at least for the exposure time employed in the study.

Analisa Hasil Sambungan Las ( Pipa STKM 13B Dan Plat SPH 440) Dengan Pengujian Tarik dan Photomacro

ABSTRACTGMAW (Gas Metal Arc Welding) is a fast, versatile welding technique that can be used in various positions, but it often results porosity in welded joints.This research aims to analysis of the welded joints of STKM13B pipe and SPD 440 plate using tensile and micro testing, using welding a current of 18 and varying voltages of 110, 130, and 150. The results is the shape of the welded joint of the plate and pipe is perfectly connected, the tensile test results showed that the ultimate strength values for specimen 1, 2, 3 (A110/V18, A130/V18, A150/V18) were (18,959, 27,886, 40,005 N) respectively. The highest ultimate strength values were obtained from the specimens (A150/V18) while the lowest ultimate strength value was obtained from specimen (A110/V18). The use of welding current strongly correlates with ultimate strength value and photomacro results, with higher currents resulting in higher density levels, minimizing porosity, and increasing ultimate strength. Keywords: GMAW Welding, Tensile Test, Macro Optical Test.

Residual mechanical properties of butt-welded ultra-high-strength steel(Q890 and Q960)after fire exposure

At present few studies have considered the mechanical properties of welded ultra-high strength (UHSS) steel after fire. In this paper, two kinds of ultra-high-strength steels Q890 and Q960 are selected as research object, and the GMAW welding method is used to connect them. An experimental study is conducted to reveal the mechanical properties of welded UHSS specimens after exposure to different high temperatures. The butt-welded UHSS and the corresponding base metal specimens are firstly heated from 200 °C to 1000 °C. After natural cooling to room temperature, the specimens are then subjected to a tensile test, and the stress-strain curves and different fracture modes are obtained. The results shown that temperature, HAZ and softening effect have an impact on the fracture mode and mechanical properties of butt-welded UHSS. Secondly, the variation law of elastic modulus of butt-welded UHSS with increasing temperature is similar to that of UHSS base metal. However, as the temperature increases, the corresponding weakening rates of yield strength and ultimate strength are significantly lower than those of the base material. Finally, based on the experimental results, prediction equations for the reduction factors of mechanical properties indicators of UHSS (base metal and welded) and HSS after fire exposure are proposed, and a comparative analysis is conducted with the existing methods. The results shown that the predictive equations proposed in this paper can more accurately calculate the mechanical properties reduction factors of UHSS (base metal and welded) and HSS after fire.

Experimental Investigation of Process Parameters on Strength of Welding Joint in GMAW

The strength value most desired in any welding process is an excellent Ultimate Tensile Strength (UTS) of the weld, compared with the parent metal. Process parameters applied during the welding process ought to be subjected to continuous scrutiny and assessment because of the ever increasing demand for structural and industrial materials with weld joints possessing higher strength values. This study is intended to investigate the inadequacies of existing GMAW welding process parameters utilized by the investigated industrial firm in its signature welding protocol, by suggesting alternative, uniquely crafted, and improved process parameters to replace its existing signature welding protocol, thereby improving the weld results by attaining higher UTS. These suggested process parameters were there after subjected to reported literature, following which optimization was achieved by employing the Taguchi Method. Then in future work we will study the strength on universal testing machine and calculating the results

Improvement in Microstructure and Properties of 304 Steel Wire Arc Additive Manufacturing by the Micro-Control Deposition Trajectory.

In this study, the GMAW welding torch was controlled by a stepping motor to achieve a periodic swing. By controlling the swing speed, a micro-variable deposition path was obtained, which was called the micro-control deposition trajectory. The influence of the micro-control deposition trajectory on the arc characteristics, microstructure, and mechanical properties of 304 steel wire arc additive manufacturing was studied. The results showed that the micro-control deposition process was affected by the swing arc and the deposition trajectory and that the arc force was dispersed over the whole deposition layer, which effectively reduced the welding heat input. However, the arc centrifugal force increased with the increase in the swing speed, which easily caused instability of the arc and large spatter. Compared with common thin-walled deposition, the deposition width of micro-control thin-walled deposition components was increased. In addition, the swinging arc had a certain stirring effect on the molten pool, which was conducive to the escape of the molten pool gas and refinement of the microstructure. Below, the interface of the deposition layer, the microstructure of the common thin-walled deposition components, and the micro-control thin-walled deposition components were composed of lathy ferrite and austenite. Compared with the common deposition, when the swing speed increased to 800 °/s, the microstructure consisted of vermicular ferrite and austenite. The tensile strength and elongation of the micro-control thin-walled deposition components are higher than those of the common thin-walled deposition components. The tensile fracture mechanism of the common thin-walled deposition components and the micro-control thin-walled deposition components was the ductile fracture mechanism.

EXPERIMENTAL STUDY THE MECHANICAL PROPERTIES OF GMAW WELDING RESULTS ON S355J2+N MATERIAL WITH POST WELD HEAT TREATMENT (PWHT)

Assembly underframe trains are a connecting process part-part into a system that has a unified function, the process of which uses GMAW-type welding. From the welding results, there is potential for the formation of residual stress which is a problem in this research, so it is minimized using the method Post Weld Heat Treatment (PWHT) thermal. The research aims to determine and analyze the effect of PWHT on the mechanical properties and microstructure of low-carbon steel type S355J2+N resulting from GMAW welding. The research method uses experiments with PWHT temperatures at 450 °C, 750 °C, and non-PWHT to find out the mechanical properties of materials, use the tensile test and micro-Vickers hardness test. Meanwhile, to determine the microstructure formed is used micro examination. The test results, were compared between the welding material with PWHT and the welding material non-PWHT. The results of the research are that the largest tensile strength value of 576 MPa was produced in the material using PWHT at a temperature of 450 °C, the largest elongation of 34.85% was produced in the material with a PWHT temperature of 750 °C, and the highest hardness value was 207.44 HV in the material non-PWHT. The conclusion of the research shows that with increasing PWHT temperature, the hardness and tensile strength values of the material decrease, and there is an increase in the ductility value of the material which is influenced by changes in the dominance of ferrite and pearlite in the material.

ANALISA PENGARUH ARUS LISTRIK PENGELASAN GMAW ALUMUNIUM 5052

Aluminum (Al) is a light metal that has corrosion resistance and good electrical conductivity. It is estimated that the use of aluminum in the future will still be wide open, both as a main material and as a supporting material, with the abundant availability of aluminum ore on earth. The welding process is one part of the manufacturing process. The welding process, which in principle is to connect two or more components, is more precisely indicated for assembling several components into a machine form. Welding Aluminum 5052 using GMAW welding with variations in welding electric current, namely 200A and 210 A, welding using the E4043 electrode. The aim of this research is to determine the strength of GMAW welded joints on Aluminum 5052 against the Charphy impact test. The GMAW welding electric current value at an electric current of 200 A produces a work force of 55.012 J and produces 0.678 J/????????2 impact charphy value, at an electric current of 210 A it produces a work force of 64.34 J and produces 0.804 J/????????2 impact charphy value. From the calculation results that have been obtained, the higher the GMAW welding electric current used causes the weld area to become more ductile, but on the contrary, the lower the GMAW welding electric current, the harder it is and tends to break easily.

PROSES PEMBUATAN TABUNG GAS 12 KG MENGGUNAKAN MATERIAL JIS-SG 255

A gas cylinder is a container in the shape of a tube and is used to store gas produced from oil refineries. The manufacturing process goes through various processes and the selection of strong materials to withstand the gas pressure in the cylinder. The main materials used in making the 12 kg gas cylinder are JIS SG 255 and SPHC. The 12 kg tube was designed with a tube height of 750 mm and a diameter of 280 mm. The SMAW welding process was carried out for the circumference and GMAW welding for the handguard and footring. To determine the area and volume of the weld on the 12 kg gas cylinder, area and volume calculations were carried out, so that it can be seen that the surface area of the 12 kg gas cylinder is 30.772 mm2, while the weld volume of the tube is known to be 115.395 cm3. Then, after welding the gas cylinder, proceed with annealing to restore the condition of the tube after welding with gradual heat temperatures, namely 200°C, 600°C and 200°C with a time of ± 14 minutes. Leak testing on tubes is carried out with two types of tests, namely hydrostatic tests and leak tests, hydrostatic tests on tubes use 31 bar water pressure with a quality of 50%, while for this leak test the tube is given air to find out whether the gas cylinder has a leak or not with a quality of 100 %.

The influence of prandtl number on flow characteristics of the fume from GMAW welding

GMAW has become one of the most popular welding methods due to its high productivity in the manufacturing industry. However, there has been agrowing concern about the health effects of the fume produced by this welding method, as it may flow into the breathing zone of the welding operator.In this study, the impact of the Pr number on the behavior of the fume flow produced by GMAW was studied numerically using Computational Fluid Dynamics (CFD) simulation. Navier-Stokes and energy equations in two-dimensional axisymmetric coordinates were used to establish the numerical model for the GMAW fume flow.A transient finite-volume method with non-staggered mesh was applied to solve the numerical model. The numerical simulations were run 2.0 ≤ Pr ≤ 15.0 with other parameters kept constant at Fr = 5.5, Re = 100, and H/X0 = 10. The time series of the spreading distance plotted at various Prnumbers show different types of distances at different stages of the fume flow, the initial maximum, the maximum, and the final distances. When the Pr number is increased from 2.0 to 15.0.the gap between the initial maximum and the maximum distances decreases while the gap between the initial maximum and the final distances decreases.A nonlinear relationship was observed when the initial maximum and final distance data were plotted against the Pr number. The best fit for the initial maximum and the final distance data were obtained using the power of -1/2 and -2/3.

Effect of Current Strength and Flow Rate of Shielding Gas on the Impact and Tensile Strength of GMAW Welsing Result on SPHC Materials

GMAW welding is one of the welds that is easy to use, especially for welding low-carbon steel that is generally widely used in the process of making frame structures, an example is a car frame which is generally made using materials that have strong, ductile, lightweight, and able to withstand impact and tensile loads when the car is used, one example of the material is SPHC. The problem is that GMAW welding results are affected by welding parameters. In this study, the parameter chosen was the strong variation of the welding current. The purpose of this study is to determine the strong influence of the current and flow rate of protective gases as well as the interaction on the impact and tensile strength of GMAW welding results on SPHC materials. This study used an experimental method with current strength parameters worth 120A,130A, and 140A as well as variations in the flow rate of protective gases, namely 15 liters/minute,20 liters/minute, and 25 liters/minute. The results of research in general, the impact strength on the weld metal has a lower result than the row material, and the tensile strength on the weld metal has a higher yield than the row material. From the study, it can be seen that the optimal current strength and flow rate of protective gas is a current strength of 140 A and a flow rate of protective gas worth 25 L /minute with an impact strength of 2.91 J/mm2 and a tensile strength of 431.72 MPa.

PRODUCTION PROCESS OF 60 FT UGL ROLLERS ON FLAT TOP (CFT) WAGON CONTAINER TYPE TRAINS AT PT. INDUSTRIAL TRAIN

A train is a form of rail transportation consisting of a series of vehicles pulled along a railroad track to transport cargo or passengers. There are different types of trains designed for specific purposes. A train may consist of a combination of one or more locomotives and attached railcars, or several self-propelled units (or sometimes a single or articulated powered coach, called a railcar). To move the train, a component called a bogie is needed. Bogies are generally used for wheels with more than 2 axles (As) in one train car. One of the bogie components found on a train is a bolster. The function of the bolster is to support the bogie against the train body. In making UGL 60 FT bolsters, it begins with material preparation. The materials used are S690Q steel with a tensile strength of 690 MPa, S355J2+N steel with a tensile strength of 355 MPa and E235 steel pipe with a tensile strength of 235 MPa. After that, it enters the cutting process, namely the process of cutting plate-shaped material using a plasma cutting machine and cutting steel pipes with a bandsaw machine, then the chamfering process, which is the process of cutting corners to form a chamfer with an angle of 0 - 90 degrees, after that the Bending process, namely the process of bending on one of the bolster components, then the assembly process, namely the process of connecting a single part of the bolster and continuing the welding process using a 350 ampere GMAW welding machine, and the last is the Quality Control (QC) process, namely the material testing process using the Non Destructive Test (NDT) method. in the form of Magnetic Test (MT) and Visual Test (VT) testing. Quality Control (QC) is carried out to check the feasibility of an object being produced. If there is a workpiece that is not good then the workpiece will be repaired again. And if the workpiece is said to be feasible, it will be brought to the assembly process in the assembly division.

Effect of cold metal transfer (CMT) on the unmixed zone formation in Stellite 6 overlays on ferritic steels

ABSTRACT The segregation of elements and formation of a UMZ is an unfavorable but inevitable phenomenon in dissimilar welding. The present study employed conventional GMAW welding and the CMT process with the same welding parameters to clad a flux-cored Stellite 6 electrode on an A516 Grade 60 steel. The effect of the CMT welding process on the formation of UMZ in the Stellite 6 overlay was investigated. OM and SEM were used to observe the cross-section of the samples. The distribution of the alloying elements across the interface between the weld and base metals was measured using EDS analysis. It was observed that the UMZ in the CMT welding process was thinner and more uniform which was attributed to the steady arc energy and convection flow during welding. Smaller heat input, lower penetration, and higher build-up were the main reasons for uniformity and reduced UMZ width.

Pengendalian Kualitas Produk Joint Break Arm di PT. Sandiya Jaya Abadi dengan Metode Six Sigma

PT Sandiya Jaya Abadi, is a company that focuses on lathe fabrication and engineering, milling/drilling, gtaw (tig), smaw, gmaw welding. This company produces various kinds of bolt components that are in motorcycles. One of them, namely, Joint Break Arm is a connection to the rear brake adjuster on a motorbike. The problems that occur in the Joint Break Arm product are, the size does not match the specified size, the diameter does not match, and the shape of the surface is rough. This study aims to analyze the root causes of product defects and to provide repair solutions for the Joint Break Arm product using the Six Sigma method. This study shows that the DPO value is 3.330791107 and the DPMO is 330791.1. As well as the Six Sigma value of, 4.914390716. From the results of the analysis of these defects, suggestions for improvements are given to reduce the number of these defects. Proposed improvements are: Organizing training to raise awareness of the importance of maintaining product and machine quality; Supervise raw materials before they are stored in the warehouse; Carry out maintenance and repair of machines regularly and continuously (sustainable); Create standard controls for checking tool posts on machines, use life time controls on zigs and create standards for mixing friction media and workpieces; Maintain all core and supporting elements to maintain a well-maintained work environment.

Study of the Effect GMAW and SMAW Welding Combination with WAAM Method

The development of technology and science is multiplying, so it affects the industrial sector in Indonesia, namely the industry that manufactures machine elements, especially in the automotive sector, which commonly uses metal as raw material. The manufacturing sector's production in the automotive industry tends to increase annually. The need for metal as raw material is constantly increasing. The WAAM welding method be utilized as one of the innovations in the industrial world that potentially reduces the use of raw metal materials by replacing them with the results of the WAAM process. In this study, a combination of GMAW and SMAW welding using the WAAM method was carried out by adding material in layers and switching between the two types of welding. The welding process is carried out by varying the current (high, medium, and low). Then, a tensile test was carried out to determine the mechanical properties of the combination results. Based on the tensile test results, it is known that the high current variation gives the best results, the increasing current lead to an enhancement of the mechanical properties. Finally, using high currents will give the best result for application in the engineering and automotive sector.

Comparative study of microstructural and mechanical properties of robotic CMT and GMAW welded 7475-T7351 aluminium alloy joints

The objective of the present investigation is to characterize the mechanical and microstructural behaviours of CMT welded AA7475 alloy in T7351 temper conditions and compare it with the GMAW welding process. The TS, YS, elongation, and hardness values are measured for both CMT and GMAW weld. It is observed that the CMT welded sample has better mechanical properties as compared to GMAW. Typical metallographic images of CMT and GMAW samples were analysed for the AA7475-T7351 joint. The dispersion of precipitates throughout the weld was assessed using EDX. In order to completely describe the failure patterns of the welded joint for both CMT and GMAW, SEM was used to analyse the fractography of WM of the fractured tensile samples. Weld metal (WM), base metal (BM), as well as the generation of the secondary phase in the heat-affected zone (HAZ), were all evaluated using EDX and SEM micrographs.

Analysis of Penetrant Test Results of S355J2 Steel Welding Connections for Qualification Welding

NDT (Non Destructive Test) is a form of testing perfomed on materials or objects without causing permanent damage to the material or objects. NDT can be used for testing materials such as concrete, steel, iron, and other. This journal aims to determine the Penetrant Test testing process on S355J2 steel welding results to determine the qualifications of GMAW Welders. Welding testing by a certified welder using GMAW welding. NDT testing was conducted in the form of a visual test and a Penetrant test when testing the weld results. The obtained data showed the welder PT. INKA is qualified with the terms and standards that have been set by the company, namely AWS D1.1 and ASTME E 165. Therefore, the Welder can be involved in the current project.

Experimental Analysis of Magnetic Particle Inspection on S355J2 Steel Weld Joints

NDT (Non-Destructive Test) is a form of testing carried out on materials or objects without causing permanent damage to these materials or objects. This study aims to determine the NDT Magnetic Particle Inspection testing process that is carried out and find out the results of the inspection of S355 J2 steel specimens with the NDT Magnetic Particle Inspection test method as the basis for determining the GMAW Welder Qualification. Welding of S355 J2 Steel is performed by a certified welder using GMAW welding using a single V-butt joint at an angle of 30 degrees. NDT Visual Test and Magnetic Particle Inspection are carried out during material testing. Data & output shows welder PT. INKA qualified with the standards set by the company, namely AWS D1.1 and ASTME E 709. So the Welder can be allowed to work on a Project because it is considered to have met the required Welder qualification standards.

Experimental Study of Crack Propagation through Cladded 316L/S355 Steel Produced by the Hot-Roll Bonding Process

A hot-rolled clad plate made of 316L stainless steel and S355 carbon steel was produced in a real industrial environment via GMAW welding, vacuuming, preheating to 1240 °C, and hot-roll bonding on four stand plate mills in nine passes with reduction rates between 22–26% per pass. The clad plates were solution annealed to achieve the usual delivery condition. Ultrasound testing showed a bonding rate of 100%. Metallographic examination revealed predominantly low concentrations of oxides at the interface. The tensile strength of the bond reached 155 MPa. The shear strength always satisfied the requirements of ASTM A264. It was observed that the concentration of oxide particles influenced the shear strength strongly. The lowest measured value was 172 MPa. Specimens notched in the base material and specimens notched in the clad layer were used in the Charpy impact test. In every case, only the notched layer broke, while the other layer was only bent. The absorbed energies were always higher than those of each material alone. Fracture mechanic tests gave similar results. The crack could not propagate from the notched layer into the other one, regardless of the material of the notched layer. Instead, delamination occurred. Due to delamination, K1c could not be determined, so KQ was given instead.