Evolution of Welding Technology

The welding technology has gone through a lot of transformation in the last few decades. The industry has seen precise automation metal welding to more effective ways and innovation in the different welding technology. From the time when metals were first heated and then hammered to get the desired shape, it has been travelled a long way to an era where metal welding has become more of a science rather than just a profession. The present literature review is based on various technologies that are involved in the welding industry along with all the issues and different aspect. On the other hand, ultrasonic welding of non-ferrous metals like copper as well as aluminium has been tried and tested procedure in the industry for several years. The process is completed rapidly depending on the size of weld node. In the present paper, a comprehensive literature review regarding metal welding technology is discussed.

Kalpakjian, Sekar and Schmid (2014) stated that modern welding techniques have been quite evolving in nature and have come a long way from the traditional use of oxyacetylene as the main component. Welding techniques have become more sophisticated and advanced during its evolving years. There has been an increase in the implementation of MIG (metal inert gases) along with MAG (metal active gas) as the main gas supply for the heat. The precision and the accurate temperature that they provide in the process is one of the many reasons why most of the metal welding industry has shifted their focus from the traditional use of oxyacetylene towards MIG and MAGs.

The MIG that uses argon and CO2 mixture have been in use throughout Australia for repair work involving thin sheets (Gao, Liu and Zhang, 2018). This is done because the above mixture provides narrow HAZ along with a much wider reduced input that not only gives an optimum temperature but also gives very low distortion. As for larger work on fabrication in the welding sector, the use of mechanical equipment that is integrated with automated MIG welding has revolutionized the more labor-intensive fabrication industry in Australia. The use of robots in the welding sector has also affected the industry in Australia and has impacted the requirement of skilled labor in the welding industry. This is due to the almost perfect input as well as the output of robotic that is implemented by them in this sector.  

Automation and Robotics in the Welding Industry

Hong and Shin (2017) mentioned that the use of Argon is restricted because of its limitation as shielding gas to low-end alloy, stainless steel. This is due to its unstable nature while attaining a higher temperature. The issue was resolved later with complex mixtures of different gases such as helium, Co2, argon, oxygen etc. In Australia, research is taking place to implement the above process for welding stainless steel along with steels with 9% nickel that can be a future arc oscillation magnetically (Pang et al. 2016). The use of tungsten arc welding has been considered as a vital core of many high-end welding industries in Australia. There has been an in-depth analysis of the process and its implication in this report too.

 The use of robots and automation in the industry has changed the overall landscape of every manufacturing sector to the extent that it has created concerns for manual labour. The welding industry has also accepted the automation and robotics and has applied that to get the flawless precision and immaculate level of welding (Nagasawa et al. 2016). This has also helped the welding sector to improve a lot in terms of its performance and precision level. There was a report by the IFR (International Federation of Robots) which said that there was an increase in demand of the industrial robot all over the world. Also, there were an estimated 1.5 million robots worldwide that were taking the high precision tasks and delivering an unmatched quality of output to their respective businesses.

Let it first discuss why the uses of automation and robotics have influenced the metal welding in Australia. The welder while welding manually had to be very attentive while executing the task. Even a slight hint of fatigue was able to change the performance and the shape of the base and the metal that has been welded (Sapanathan et al. 2016). The application of molten weld and the holding of arc were one of the most error-prone processes in welding. It had to be very difficult for the welder to execute these processes while simultaneously he had to cleat the slag. This along with the exposure of high-intensity light and heat was always considered the prime reasons for the error that happened in the welding process.

Robots were able to eliminate the entire issue of human error that was there in the welding industry in Australia. The automated and detailed calibrated welding machines were used to make both the input as well as the output error free.  All the parameters that are required by the welding industry are set in advance in the computer network that is integrated with the robots (Long et al. 2018). These parameters are the reason as to why the arc in the welding machine along with the melted metal is applied with utmost precision in Australian welding industry.

Latest Research on Welding Technology

Mvola, Kah and Martikainen (2014) mentioned that it should be seen that computerized optimization is also a very efficient way that has been integrated with the welding process that has made this sector much more profitable for the metal manufacturing industry. Automation and computerized machines have helped the sector to manufacture welded metals of different shapes and sizes without any error.  Now that it is known about the use of robotics in welding, let it now discuss various about various researches that have been done on welding (Poonnayom et al. 2015). It is very important to know about these researches in the welding industry. Most of the researches in the automation sector have been done in the last one and a half decade.

The one substantially found out the relationship between variables and bead-penetration that are involved in robotics. This important research involved a four-level change in variables. These were arc-voltage, welding angle, and welding speed along with welding current. These are the important variables while considering the bead-penetration. In this process, S400 flat along with 200mm*75 mm* 6 mm is to be taken as the base metal. The various effects on the bead-penetration is discussed extensively (Abe and Sasahara 2016). There was also an implementation of an empirical model that was used to extend the welding process to match with different thickness of the metal.

The breakthrough in the implementation of the neural network that was responsible for the arc welding optimization. The different parameter like welding current, its speed, and arc voltage was now could be chosen for the different input variables that are to be used for controlling dead-width. The use of the propagation algorithm and the lavenberg-Marquardt theorem also were also integrated into the process (Totey et al. 2017). There was also a comparison done by their respective result in performance, it was thus suggested that the latter had the maximum utility of in the process.

It able to successfully place the most appropriate reason for the inaccuracy of the robotics in welding. It was able to identify that because of the lack of expertise by the programmers of the robotics system, the selection of variables was not done in a very accurate manner. This was primarily the reason for the inaccuracy of the welding process in spite of using robotics for it. There was then a valid suggestion of using regression method to prevent in robotics (Guo et al. 2015). Later, it was seen that Taguchi’s technique along with fuzzy regressive methods was implemented which were able to get an optimal bead-width.

The study of various prediction that was based on bead-geometry in various welding systems. All the above-stated methods were used such that the bead optimization could be achieved. All the related SPSS were also deployed for continuing all empirical works. There was also a requirement of deployment of a certain model and later there was also an analysis on the various algorithm for controlling of various process. Brassington and Colegrove (2017) embarked some light on the quality of robotics engineered welding system and also commented that the overall performance and quality of the proper weldman was not being achieved which was the due to many difficulties involving mathematical welding.

 According to AWS, welding is considered as a location-specific process and can be said as a coalescence in metal. It is a mentioned fact that the whole process of welding involves a metal or non-metal to be heated in order to get a required liquified temperature, which would then assist the metal in sticking or joining with the other metal. This was initially done in a supervised environment, but later it became widespread with the invention of arc metal rod. Either these processes could be carried out through the application of pressure or even without the application of pressure; this also depends on the nature of the weld. There might be certain cases when a filler metal could be used if there is a requirement for the application of pressure (Sanga, Wattal and Nagesh 2018). The research was successful in finding out that even a fused layer was enough for holding the weld. But, during this process of implementing fused layer, caution must be taken to avoid any waste of energy along with any weldment sag. The fused has also been evolved through various rigorous researches that were able to successfully identify the exact amount of physical dimension needed to avoid wastage of energy and power. These physical parameters were its width, thickness, mechanical as well as metallurgical properties. Along with this, there was research done on the different parameter of techniques and methods such as fractional-factorial along with response-surface mechanisms with many mathematical models (Skar et al. 2016). Let it now see the most important techniques that is utilized in the bead-geometry in welding Industry in Australia.

It has been investigated the pulsed metal gas arc welds. This was done by implementing various fractional as well as D-optimal designs.  There was also a development of a model just to determine the feed rate and its response under the different pulsing that was given. The conclusion was done by the development of a very simple linear wire and its feed rate that was done for increasing the productivity of the welding (?abanowski et al. 2016). There were also various techniques that were initiated by many researchers to make an assumption of bead-geometry of steel. Many experiments were done on the following years on various wire feed and it rate fluctuation on the different pulsing situation.

All the above process was done to get to the important aspect of Factorial Techniques. It was successful implementation of the researches, suggested the application of these empirical equations must be integrated with the programming of these welding machines in order to get the best-desired result through them (Shao et al. 2017). Now that it is discussed various initial theories in welding, there are any welding methods that are specifically used in the metal industry along with any manufacturing industry that also has to be discussed in this report. Along with the major welding techniques, narrow gap methods are the most successful among all. Let it now see the different narrow gap welding methods that are used extensively in all the welding industry in Australia.

NG-GTAW principal involves using of contact tube that is insulated with cold water; also, it has a tungsten electrode that is non-consumable. The filling of the joint gap requires a separate addition of a filler metal that will provide an adequate amount of weld metal (Wu et al. 2018). This filler metal may be added manually by majorly it is added automatically. This automatic process of wire feeding can be done by hot or cold wire. This process is preferable for metals that are special as opposed to routine metals.

The welding head for NG-TAW consists of three slides which are mutually perpendicular (transverse as well as vertical to weld the slides which are motorized, joystick controlled), a wire feeding system (diameter being 1.6mm), an (AVC) arc voltage controller and lastly welding torch. AVC comprises vertical slides that are motorized and voltage sensor. The voltage is maintained by measuring arc voltage and keeping the torch in a vertical position by adjusting it automatically.

Features of the process:

1. Capacity to produce higher joint integrity in every welding position
2. Heat input should be low
3. There should be no spattered
4. Arc stability should be high
5. No provision of slag formation
6. Weld metal quality should be excellent
7. GTAW process requires high fracture toughness as well as strength

NG-GTAW Torches: Bear a similarity to conventional GTAW torches. But, a guide for the filler wire and contact tube are extended so that they reach the bottom of a narrow deep groove (Liu et al. 2015). A hot wire is taken; contact tip of it is insulated from electrical ground (last point of contact physically to the wire) before entering weld pool.

In case the material has a thickness until 40mm, conventional TIG machine torch along with gas shielding nozzles may be used just above the top surface of the mentioned joint.

In order to achieve greater thickness, usage of narrow gap GTAW torch has to be used along with a secondary surface gas box that will ensure that the shielding is done adequately.. The primary nozzle provides central flow of gas around tungsten electrode during which, secondary nozzle would provide side flow in the front and the rear areas, in respect to direction of welding (Ahsan et al. 2016). This arrangement is adopted as it ensures adequate protection of tungsten electrode, wire and weld pool within the groove, while supplementary protection is required by top passes which are provided by a shielding box, located just above it. Control of sidewall penetration is achieved by oscillating tungsten electrode either mechanically or by the mechanic field.

NG-GTAW torches are generally elongated. Shielding gas has to be delivered to the either side of electrode in the rectangular slots and gas may be supplied additionally through holes in either side of blade. For NG-GTAW, along with accurate controlling of torch linear movement, maintenance of arc length is important to control heat input.

NG-GTAW wire feeding systems: Both the hot and the cold wire techniques bear a similarity to the conventional GTAW (Khodabakhshi et al. 2017). However, there is high requirement of without defect performance, thus leading to a concern in repairing NGW. In case of a feeding system employing hot wire, wider speed range of wire must be provided as opposed to cold wire. In hot wire system, the speed range from 2.1 to 211.6 mm/s is useful. NG-GTAW that has addition of cold wire filler has the capacity of welding narrow gap.  NG-GTAW with the addition of hot wire is a better alternatives and it has capacity of high rate of deposition.

Applications:

1. Automatic NG-GTAW process of high accuracy was developed so that it can join 50mm steel plates of ultra-high strength that can be used in deep submersibles to make the pressure hull.
2. NG-GTAW is generally used for titanium along with its alloys, stainless steels, ultra-high strength and high strength low alloy (Prasomthong, Sangsiri and Kimapong 2015).

Problems:

1. Arc stability may be affected by draughts, especially in the open areas where production is taking place. It can be remedied by employing plastic tents to enclose the welding area.
2. Automatic controlling of arc length results in problems in a NG-GTAW torch, when establishment of plasma track takes place between groove sidewall and side of tungsten. This results in low reading of voltage, which leads to the AVC lifting the tungsten up, thus automatically leading to breaking of the path. The tungsten may get thrown into the weld pool by this vertical oscillation (Fukuda 2017). This situation can be remedied by introducing another gas flow along the joint walls parallel, thus resulting in removal of the “dead area” of gas in the tungsten side.

Continuous research in the shipbuilding institute in Leningrad has resulted in a new discovery that better quality of welds would be obtained by narrow gap shielded metal arc welding (Chen et al. 2016). In order to achieve this welding current of respective diameter has to be ascertained first according to the aforementioned instructions of industry.

If welds are being made in vertical position, recommendation is there to reduce current by 10% in every electrode diameter. Either vertical position welding or flat position welding with NG-SMAW is far better than normal welding methods according to the researches that has been undertaken. The advantages are:

1. Reduction of deformation as the heat input applied to the metal point is reduced to a great extent.
2. No Requirement of complex shielding device due to the molten metal
3. No need of insulation to avoid short circuit

Application of NG-SMAW is done in onsite joining of rails. A manual arc using an electrode that is coated with low hydrogen does this welding process. For  this process, and groove of dimension 10-14 mm is obtained, with copper backing it is taken in between the rail ends and is then set, then preheating takes place. The slag is removed from bottom and then laying of a multiple-layer weld takes place. After this process, a clearance of 2-4mm is maintained from both web and top of rail. Installation of copper shoes is done (Ghosh, Pal and Nandi 2016). Then melting of the groove face has to be done, thus this process is completed by using the arc from bottom surface. The gap is gradually filled with the help of the fused metal. The overflowing slag that gets formed in vicinity of the molten pool is made to escape by the gap. Thus, no requirement of slag removal until the process of welding has been done with. After this continuous welding process, there is very less chance of presence of slag impurities. Reason for this is, the produced slag possesses low viscosity even at higher temperature as well as lower specific density. Due to these properties, slag can very easily disassociate itself from molten metal similarly to the floating of oil just on the surface the water. Annealing process has to be done after the welding so that stress gets released, then grinding of the whole joint is done to remove the reinforcement. Only then, the process gets done with.

Features of the process:

1. If welding is done using thickly coated electrodes and narrow grooves, also keeping in mind that the deep gap is lesser than 20mm then only the welding can be done using NG-SMAW (Tenner et al. 2015). Then only the slag crust will be able to be removed from bead in succession.
2. However in case of no removal of slag, crust is the objective then the gap needs to be filled vertically, the whole of the height.
3. The bead extension of the gap being small results in electrode moving back as well as forth inside gap leads to slag continuously being in the heated condition and repeatedly melting.
4. The steady increase of slag quantity may take place, due to it being free to move outside that of the gap.
5. Excess slag removal from gap can only take place if an inclination of 10-15 degree is maintained from a vertical position towards welder.

Advantages:

It has been observed that if welding is done using a 25mm HSLA steel plate using the process of NG-SMAW. On comparison of its metallurgical as well as mechanical properties with that of the normal V groove it was found:

1. Narrow groove joint shows higher tensile strength.
2. Narrow groove welding has higher impact toughness
3. Less transverse shrinkage in a narrow groove
4. The microstructure is finer in narrow groove

2.7 NG-SAW (Narrow Gap Submerged Arc Welding)

The process of NG-SAW involves flux addition by employing a hopper that is present in the vicinity of the contact tube. Then creation of arc is done, which results in generation of molten metal under flux cover. Removal of melted, solidified and powdered flux is necessary after each flux completion.  

Features of the process:

Produce weld along with better bead shapes

1. No spatters
2. Rate of deposition is high
3. Mechanical properties of weld to be ascertained by suitable selection of flux and/or wire combinations.
4. Time, material and labour efficient due to transition.

NG-SAW torches: They are much simpler as compared to the complex variety of the NG-SMAW, due to non-subjection to spatter as well heat-radiation. The thickness of the plate used for welding can be extended by changing the number of torch extensions that needs to be attached to contact tube. The current transfer may be impaired if thick wire is use in the contact tip. This situation can be remedied by pressing the wire to contact tip using spring tension.

NG-SAW wire feeding system: Even its wire feeding system is simpler compared to others. However, additional device is required for alternate torch rotation. Wire straightening device is also required.

Problems:

1. Choking up of welding nozzles, due to transverse shrinkage. The situation can be remedied by a preset or slight angle along with the “strong backs”.
2. If the set-up is poor with elding bead it can result in the lack of fusion in the sidewall.
3. Shrinkage cracks can appear if there is preheat lack. This situation can be remedied by preheating subsequent welds, 2.5 hours before the welding process.
4. Flux and/or wire combination selection should be done keeping in mind the parent material.

Drawbacks:

1. Visual observation of arc is absent.
2. It is very difficult to remove slag after every slag completion, so an additional device is used.
3. Overheating is another problem of the weld nozzles.
4. Accidental arc strikes may occur in between contact nozzles and sidewall.

Thus, it can be concluded that narrower the joint gaps and smaller preparation angles, could definitely lead to huge improvements in efficiency as well as productivity. All the different references have been use to support the claims that are made in the report. Along with that, the above report has all the essential information regarding the metal welding techniques that are use in Australia.

Understanding the theories and framework for metal welding technology is important to develop a research about the topic. As it is important to conduct the research in proper way, research methodology would be helpful to achieve that (Bauer 2014).  There are three types of research philosophy such as positivism, interpretivism and realism philosophy. In the current research, positivism philosophy has been selected in the research. The idea of knowledge appears as profound as it involves in developing knowledge for covering the research topic. Selection of positivism philosophy has an impact on the process where important philosophical differences are existed in the research. However, as the research does not deal with humanistic qualitative methods, interpretivism philosophy has been rejected in the research.

In the current research, deductive research approach is selected in the research. As the research approach allowed the researcher to refer the existing theories and concepts regarding metal welding technology, the approach is suitable for the research. The research designs are important as the complete research design tends producing significant conclusion (Choy 2014). It was helpful to collect necessary data during analysis of the project.  Strategies used several research in research like descriptive research design and correlation research design. In the research, descriptive research design has been selected.  

Data collection method assists the researcher gathering data from primary and secondary sources (Dang and Pheng 2015). In the current research, secondary data has been collected for the research. The data helps in perception of the research topic during helping in extracting the data based on the demands. Qualitative data analysis has been followed in the research.

As the effect of welding on a metal can be not always predictable i.e how the shape and of the component will respond along with its performance, it is advisable that all the initial designs in an industry should be revised regularly. Also due to the advancement in technology in welding, the evolutionary algorithm along with numerical optimization can be effectively used to deal with any possible error or undesirable mechanical change. This can further claim to have enhanced the space of virtual welding in Industries. There has been many research and implementation based experiment for finding out the viability of DoE (design of experiment), the evolutionary algorithm along with computational network in Australia welding industries. All the above-stated mechanism in virtual welding has been shown to have a positive effect on the overall result of the weld. It has been seen in Australia, that even in order to establish a relationship through various inputs and output in welding to get an optimized result, there has been a failure by the different manufacturer in Australia to actually control various parameters which is very beneficial for getting errorless bed-geometry along with the best quality weldment.

Various reference literatures have also been studied while in the process of making the report. In any metal, related industry welding is an integral part of all the major processes that are done in it. It can be said that metal welding is the most preferred technology available today when it comes to assembling various structure or implementing any specific design. One of the noticeable aspects of metal welding is that it is multiple inputs as well as the output process. There are many categories and differentiation of the welding sector, like its bead geometry, its mechanical properties along with the overall distortion. It will try to analyze the various aspect of it in the later section. The primary objective behind any metal welding process is to get the highest possible weldment quality with an almost perfect bead- geometry of the welding along with flawless mechanical property and distortion that is as low as possible.

References

Abe, T. and Sasahara, H., 2016. Dissimilar metal deposition with a stainless steel and nickel-based alloy using wire and arc-based additive manufacturing. Precision Engineering, 45, pp.387-395.

Ahsan, M.R., Kim, Y.R., Kim, C.H., Kim, J.W., Ashiri, R. and Park, Y.D., 2016. Porosity formation mechanisms in cold metal transfer (CMT) gas metal arc welding (GMAW) of zinc coated steels. Science and Technology of Welding and Joining, 21(3), pp.209-215.

Bauer, G.R., 2014. Incorporating intersectionality theory into population health research methodology: Challenges and the potential to advance health equity. Social science & medicine, 110, pp.10-17.

Brassington, W.D.P. and Colegrove, P.A., 2017. Alternative friction stir welding technology for titanium–6Al–4V propellant tanks within the space industry. Science and Technology of Welding and Joining, 22(4), pp.300-318.

Chen, S., Li, H., Lu, S., Ni, R. and Dong, J., 2016. Temperature measurement and control of bobbin tool friction stir welding. The International Journal of Advanced Manufacturing Technology, 86(1-4), pp.337-346.

Choy, L.T., 2014. The strengths and weaknesses of research methodology: Comparison and complimentary between qualitative and quantitative approaches. IOSR Journal of Humanities and Social Science, 19(4), pp.99-104.

Dang, G. and Pheng, L.S., 2015. Research methodology. In Infrastructure Investments in Developing Economies (pp. 135-155). Springer, Singapore

Fukuda, M., 2017. Advanced USC technology development in Japan. In Materials for Ultra-Supercritical and Advanced Ultra-Supercritical Power Plants (pp. 733-754).

Gao, X.L., Liu, J. and Zhang, L.J., 2018. Dissimilar metal welding of Ti6Al4V and Inconel 718 through pulsed laser welding-induced eutectic reaction technology. The International Journal of Advanced Manufacturing Technology, 96(1-4), pp.1061-1071.

Ghosh, N., Pal, P.K. and Nandi, G., 2016. Parametric optimization of MIG welding on 316L austenitic stainless steel by grey-based Taguchi method. Procedia Technology, 25, pp.1038-1048.

Guo, N., Du, Y., Feng, J., Guo, W. and Deng, Z., 2015. Study of underwater wet welding stability using an X-ray transmission method. Journal of Materials Processing Technology, 225, pp.133-138.

Hong, K.M. and Shin, Y.C., 2017. Prospects of laser welding technology in the automotive industry: A review. Journal of Materials Processing Technology, 245, pp.46-69.

Kalpakjian, S., Vijai Sekar, K.S. and Schmid, S.R., 2014. Manufacturing engineering and technology. Pearson.

Khodabakhshi, F., Haghshenas, M., Chen, J., Shalchi Amirkhiz, B., Li, J. and Gerlich, A.P., 2017. Bonding mechanism and interface characterisation during dissimilar friction stir welding of an aluminium/polymer bi-material joint. Science and Technology of Welding and Joining, 22(3), pp.182-190.

?abanowski, J., Prokop-Strzelczy?ska, K., Rogalski, G. and Fydrych, D., 2016. The effect of wet underwater welding on cold cracking susceptibility of duplex stainless steel. Advances in Materials Science, 16(2), pp.68-77.

Li, J., Sun, Q., Liu, Y., Cai, C. and Feng, J., 2017. Cold Metal Transfer Welding–Brazing of Pure Titanium TA2 to Aluminum Alloy 6061?T6. Advanced Engineering Materials, 19(2), p.1600494.

Liu, F.C., Liao, J., Gao, Y. and Nakata, K., 2015. Effect of plasma electrolytic oxidation coating on joining metal to plastic. Science and Technology of Welding and Joining, 20(4), pp.291-296.

Long, J., Huang, W., Xiang, J., Guan, Q. and Ma, Z., 2018. Parameter optimization of laser welding of steel to Al with pre-placed metal powders using the Taguchi-response surface method. Optics & Laser Technology, 108, pp.97-106.

Mvola, B., Kah, P. and Martikainen, J., 2014. Dissimilar ferrous metal welding using advanced gas metal arc welding processes. Reviews on Advanced Materials Science, 38(2).

Nagasawa, T., Otsuka, M., Yokota, T. and Ueki, T., 2016. Structure and mechanical properties of friction stir weld joints of magnesium alloy AZ31. In Essential Readings in Magnesium Technology (pp. 517-521). Springer, Cham.

Pang, J., Hu, S., Shen, J., Wang, P. and Liang, Y., 2016. Arc characteristics and metal transfer behavior of CMT+ P welding process. Journal of Materials Processing Technology, 238, pp.212-217.

Poonnayom, P., Chantasri, S., Kaewwichit, J., Roybang, W. and Kimapong, K., 2015. Microstructure and Tensile Properties of SS400 Carbon Steel and SUS430 Stainless Steel Butt Joint by Gas Metal Arc Welding. International Journal of Advanced Culture Technology, 3(1), pp.61-67.

Prasomthong, S., Sangsiri, P. and Kimapong, K., 2015. Friction Stir Spot Welding of AA5052 Aluminum Alloy and C11000 Copper Lap Joint. The International Journal of Advanced Culture Technology, 3(1), pp.145-152.

Sanga, B., Wattal, R. and Nagesh, D.S., 2018. Mechanism of Joint Formation and Characteristics of Interface in Ultrasonic welding: Literature Review. Periodicals of Engineering and Natural Sciences, 6(1), pp.107-119.

Sapanathan, T., Raoelison, R.N., Buiron, N. and Rachik, M., 2016. Magnetic pulse welding: an innovative joining technology for similar and dissimilar metal pairs. Joining Technologies, pp.243-273.

Shao, Q., Xu, T., Yoshino, T. and Song, N., 2017. Multi-objective optimization of gas metal arc welding parameters and sequences for low-carbon steel (Q345D) T-joints. Journal of Iron and Steel Research, International, 24(5), pp.544-555.

Skar, J.I., Gjestland, H., Oosterkamp, L.D. and Albright, D.L., 2016. Friction stir welding of magnesium die castings. In Essential Readings in Magnesium Technology (pp. 523-528). Springer, Cham.

Tenner, F., Berg, B., Brock, C., Klämpfl, F. and Schmidt, M., 2015. Experimental approach for quantification of fluid dynamics in laser metal welding. Journal of Laser Applications, 27(S2), p.S29003.

Totey, A.B., Lad, A., Takote, A., Dhawale, K. and Yadav, B., 2017. Effect of Welding Parameters on the Mechanical Properties and Microstructure of BQ Plateastm SA 516–60 Grade. International Journal on Recent and Innovation Trends in Computing and Communication, 5(6), pp.753-756.

Wu, W., Zhao, M., Wang, H., Zhang, Y. and Wu, T., 2018. Twin-Wire Pulsed Tandem Gas Metal Arc Welding of API X80 Steel Linepipe. International Journal of Corrosion, 2018.