scholarly journals Optimization of Metal Inert Gas Welding Process during Joining of Structural Steels- An Overview

2020 ◽  
Vol 184 ◽  
pp. 01028
Author(s):  
Ravindra Kumar Misra ◽  
Rajesh Kumar Porwal

Metal Inert Gas welding is a fast, reliable and cost effective technique for joining of different ferrous materials and steels used in the construction of large structures like Fe410WA, IS2062, SS304, AISI1040 and AISI316 etc. To obtain better quality and performance of the steel welded joints, parameter optimisation of metal inert gas welding procedure and weld heat treatment process is carried out. In optimization work and studies, variables of GMAW process like welding voltage and current, speed of welding, WFR (rate of wire feed), GFR (rate of gas flow), type of gas used and effect of heat treatments are kept changing to get best combinations of input parameters for best quality of welded parts. The quality of welds is evaluated in terms of mechanical properties of welded joints like ultimate tensile and yield strength, elongation, microstructure, heat affected zone and defect free weld joints etc. Model and experimental studies are done in different combinations to get best combination of input parameters for steels. Studies by authors have identified the significance of input parameters in ascending order and some of them also quantified the optimal values of the input parameters. Pre and post weld heat treatment of structures is beneficial in improvement of mechanical and fatigue properties.

2020 ◽  
Vol 5 (2) ◽  
pp. 140-144
Author(s):  
Wenny Marthiana ◽  
Yovial Mahyoedin ◽  
Duskiardi Duskiardi ◽  
Afri Rahim

AbstrakPada proses produksi, pengaturan parameter poses memegang peranan penting terhadap tercapainya mutu produk yang dihasilkan. Pada proses pengelasan, salah satu parameter proses pengelasan yang harus diperhatikan adalah besar arus pengelasan. Kajian ini dilakukan untuk mengetahui besar kuat arus yang sesuai pada proses pengelasan material ST 37 menggunakan proses pengelasan MIG (Metal Inert Gas).  Pengujian dilakukan dengan memvariasikan besar kuat arus pengelasan yaitu pada 90A, 100A, 110A serta 120A. Pengujian tarik dilakukan terhadap hasil pengelasan tersebut. Hasil pengujian tarik menunjukkan, pengelasan menggunakan kuat arus sebesar 110A memberikan nilai yang maksimum pada beberapa besaran pengujian.  Untuk nilai tegangan tarik, σ memiliki nilai 16.9 kg/mm2, modulus elastisitas, E, 3.14 kg/mm2 serta Regangan ε, 5.42%. Kata kunci: pengelasan, Metal Inert Gas, Tegangan Tarik, modulus elastisitas  AbstractThe appropriate production parameter process plays an important role in fulfill the quality of the products such as mechanical properties like tensile strength and percentage of elongation of MIG welded joints.  Likewise, in the welding process, one of the welding process parameters that is welding current must be considered, since the welding current is most influential parameters affecting weld penetration, deposition rate, weld bead geometry and quality of weld metal. Variation of welding current on MIG (Metal Inert Gas) welding process on ST 37 specimen   was to examine the effects on like tensile strength and percentage of elongation and elasticity modulus.  From the experiment, it is found that when welding current increased up to 110 Ampere the tensile strength tends to incline then slightly decline when welding current increased, modulus elasticity value and percentage of elongation value as well.  The maximum value of tensile strength 16.9 kg/mm2 percentage of elongation value 5.42%. and modulus of elasticity 3.14 kg/mm2 were gained at 110 ampere welding current Keywords: welding process, Metal Inert Gas, Tensile strength, elasticity modulus ,percentage of elongation


Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 583 ◽  
Author(s):  
Robert Kosturek ◽  
Lucjan Śnieżek ◽  
Marcin Wachowski ◽  
Janusz Torzewski

The aim of this research was to investigate the influence of post-weld heat treatment (PWHT, precipitation hardening) on the microstructure and fatigue properties of an AA2519 joint obtained in a friction stir-welding process. The welding process was performed with three sets of parameters. One part of the obtained joints was investigated in the as-welded state and the second part of joints was subjected to the post-weld heat treatment (precipitation hardening) and then investigated. In order to establish the influence of the heat treatment on the microstructure of obtained joints both light and scanning electron microscopy observations were performed. Additionally, microhardness analysis for each sample was carried out. Fatigue properties of the samples in the as-welded state and the samples after post-weld heat treatment were established in a low-cycle fatigue test with constant true strain amplitude equal to ε = 0.25% and cycle asymmetry coefficient R = 0.1. Hysteresis loops together with changes of stress and plastic strain versus number of cycles are presented in this paper. The fatigue fracture in tested samples was analyzed with the use of scanning electron microscope. Our results show that post-weld heat treatment of AA2519 friction stir-welded joints significantly decreases their fatigue life.


Author(s):  
Rajesh Singh ◽  
Gaurav Yadav

This paper reports on process parameter selection for optimizing the weld pool geometry in the metal inert gas welding of High strength low alloy (HSLA) steel. The experimental studies were conducted under varying Voltage, flow rate, stick out and wire feed speed. The settings of welding parameters were determined by using the Taguchi experimental design method. The level of importance of the welding parameters on the weld pool geometry is determined by using analysis of variance (ANOVA). The optimum welding parameter combination was obtained by using the analysis of signal-to-noise (S/N) ratio. The confirmation tests indicated that it is possible to optimize the weld pool geometry significantly by using the Taguchi method. The experimental results confirmed the validity of the used Taguchi method for enhancing the welding performance and optimizing the welding parameters in the metal inert gas welding process.


2017 ◽  
Vol 265 ◽  
pp. 755-761 ◽  
Author(s):  
A.K. Tingaev ◽  
M.A. Ivanov ◽  
A.M. Ulanov

We have investigated a possibility of obtaining high-quality welded joints after oxygen and plasma cutting of steel С355 without removing the heat-affected zone (HAZ), in which the changes in chemical, phase and structural compositions are observed. Numerical and experimental studies of the effect of heat input of MAG and Submerged Arc welding on the quality of welded joints are performed. In particular, it was found that when the heat input of welding is at least 6.5 kJ/cm, the metal of HAZ of the edges after cutting is heated during the welding to temperatures above Ас3, which leads to its full recrystallization. When the heat input of welding is at least 10 kJ/cm, the edges after cutting are completely melted and become a part of the welding seam metal. The presence of extensive areas of melting and recrystallization of the edges in the welding process contributes to obtaining high-quality welded joints without removing the HAZ of the edges after cutting. To verify the results of numerical studies, experimental tests of control welded joints were conducted, which showed that the values of bending angle and impact toughness of the welding seam metal and heat affected zone are significantly above the regulatory requirements to quality of welded joints, and not less than the same requirements for steel С355. The obtained results confirm the possibility of revising domestic regulatory requirements for the steel constructions production in terms of the preparation of edges for welding using technologies of thermal cutting without subsequent machining.


The article deals with promising areas of application of pulsed laser welding for products made of silver-based alloys. The results of experimental studies on the choice of modes of pumping, defocusing to improve the quality of the weld and the efficiency of the welding process.


Author(s):  
Ajay A. Kardak ◽  
M. A. Wahab

Aluminum alloys because of their high strength to weight ratio have various applications as structural material in railways, ship building, aeronautics, construction, and consumer appliances. This increased use of aluminum alloys calls for more efficient and reliable welding processes which has always represented a great challenge for designers and technologists. AA-6061 Aluminum Alloy (Al-Mg-Si) is widely used in the aircraft industry and has gathered wider acceptance in the fabrication of light weight structures. The preferred welding process for this alloy is Tungsten Inert Gas (TIG) process due to their comparatively easier applicability, high yield, and better economy. Major difficulties are associated with this type of welding process, such as, the presence of tenacious oxide layer, high coefficient of thermal expansion, solidification shrinkage, solubility of hydrogen, and other gases in the molten state. Furthermore, problems such as decay of mechanical properties due to phase transformation and softening can occur in the heat-affected-zone (HAZ). Post weld heat treatment can be used to improve the strength of the HAZ for heat-treatable alloys like AA-6061. Hence, the major objectives of this work was to conduct a systematic study and gain an in-depth understanding of the effect of post-weld heat treatment (PWHT) of these joints on tensile properties, micro hardness, microstructure, and fracture surface morphology of butt-welded joints. It was found that of all the PWHT processes, Age-hardening (AH) resulted in superior mechanical properties and hardness. The reason for this enhanced strength has also been studied from metallurgical point of view. Microstructure and fracture surface of the tensile tested specimens were studied using light microscope and scanning electron microscope, respectively. Correlation has been drawn between the tensile test results, microhardness and the metallurgical results. It was found that the uniformly dense precipitation of fine Mg2Si, and the lack of precipitate-free zone could be the reason for the superior results found.


Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5128
Author(s):  
Jaroslaw Szusta ◽  
Nail Tüzün ◽  
Özler Karakaş

The current study investigates the load controlled fatigue properties of the microplasma arc welded thin titanium Grade 5 (6Al-4V) sheets. In order to explore the effect of weld geometry on the fatigue, two different welded joints were used in the experimental studies. Load controlled fatigue test results were evaluated to present an outlook on the behaviour of microplasma welded titanium alloy Grade 5 sheets under cyclic loading. Even though the previously published monotonic tests showed successful use of microplasma arc welding to join thin titanium Grade 5 sheets with mechanical properties comparable to the base metal, fatigue life of the welded joints was lower than the lives of samples without welds. In particular, the fatigue performance of overlap joints was very poor. This was presumed to be due to the changed material properties of the heat affected zone which was formed by the excess heat of the welding process as fractures often occurred at such locations. Based on experimental findings and fractographic observations, a clear adverse effect of welding process in material behaviour was discovered. Despite the concentrated heat of microplasma arc welding, post-weld heat treatment of the weld area is recommended to improve the mechanical behaviour of the welded joints.


2016 ◽  
Vol 716 ◽  
pp. 907-914 ◽  
Author(s):  
Nikola Sibalic ◽  
Milan Vukcevic

Experimental researches that were performed in order to determine the mechanical parameters in the process of joining of materials using the FSW process are presented in this paper. The paper presents the joining of CuETP sheet copper alloy, with thickness of 5 mm, and provides details of the friction stir welding process. Besides that, the influence of tool geometry and the regime of welding on the quality of welded joints, was investigated. Experimental studies are made on the basis of the adopted multifactoral orthogonal plan, with varying of factors on two levels and repetition in the central point of the plan. Parameters varied in the experiment were: welding speed, rotation speed of tool, angle of pin slope, pin diameter and shoulder diameter. The family of tools is provided, based on the adopted geometric parameters. The experiment was carried out in a laboratory at ambient temperature in conditions similar to those in the production. In order to determine the quality of welded joints, mechanical tests were performed in the paper, and tensile strength and impact toughness were determined.


Author(s):  
Isiaka Oluwole Oladele ◽  
Samson Adelani Oluwagbenga ◽  
Joseph Ajibade Omotoyinbo

In this study, 8011A aluminum alloy was subjected to artificial ageing and joined by tungsten inert gas (TIG) welding process. The effect of welding process on the mechanical (hardness, tensile, impact) properties, corrosion resistance and microstructure of the artificially aged and welded joints were investigated. The sample was divided into pre weld heat treated and as received samples. The pre weld heat treated sample was subjected to solution treatment at 500 °C, soaking for 1 hour, and quench in water before artificial ageing was carried out at 180 °C with holding time of 8 hours. Both the pre heat treated and the as received samples were welded using tungsten inert gas (TIG) welding process. It was observed from the results, that the pre weld heat treatment adopted improved the mechanical properties and corrosion resistance of the weldments in some of the properties examined. In comparison with the welded samples, the hardness, tensile yield strength and corrosion resistance of the pre weld heat treated samples were significantly improved. There was an improvement of 11% in hardness, 9% in yield strength and 92 % in corrosion resistance when immersed in 3.5 wt% NaCl solution.


Sign in / Sign up

Export Citation Format

Share Document