ISSN 2321 3361 © 2021 IJESC Research Article Volume 11 Issue No. 03 Experimental Investigation of Plasma Arc Welding In Dissimilar Materials AISI 304 and Monel Alloy 400 Using Swarm Algorithm Mr.R.Prakash1, Agilan S 2, Barath A S 3, Deepak N 4 and Dhinesh Babu D5 Assistant Professor1, Students 2, 3, 4, 5 Kongunadu College of Engineering and Technology (Autonomous), Tamil Nadu, India1, 2, 3, 4, 5 Abstract: The nature of welding in the aeronautical industry is characterized by low unit production, high unit cost, extreme reliability and severe service conditions. These characteristics point towards more expensive and more concentrated heat sources such as plasma arc, laser beam and electron beam welding as the processes of choice for welding of critical components. Among various precision welding processes, Plasma Arc welding has gained importance in small and medium scale industries manufacturing bellows , diaphragms etc because of less expensive and easy to operate. This project the works on Plasma Arc welding and associated phenomena such as welding voltage (WV), welding Current (WC), welding Time(WT) and nozzle to plate distance(NTPD) on important parameters in dissimilar materials AISI 304 And monel alloy 400 joints. The project focuses on weld quality characteristics like welded micro structure, hardness and impact of dissimilar welded joints Keywords: Plasma Arc welding, welding voltage (WV), welding Current (WC), welding Time(WT) and nozzle to plate distance(NTPD), dissimilar materials AISI 304 And monel alloy 400 1. INTRODUCTION 1.1 WELDING Welding is a metal joining process that is used for joining two or more similar metallic work pieces (or thermoplastics) by the application of heat. It finds its application in a large number of industrial processes. Welding can be done either by melting and solidifying metals or by the application of pressure and heat. The quality and lifetime of weld can be improved by Figure 1.1 plasma arc welding Setup providing after-treatment to the weld. High Frequency Impact Treatment (HiFIT) is an example of after-treatment provided The plasma arc welding is method wherever a coalescence is to welded joints to improve their fatigue strength. Welding can generated with the temperature which is developed from a be used to produce five main joints. These joints can be sub- special setup between a tungsten alloy electrode and the water- categorized. The five main welded joints are listed below: cooled nozzle (Non transferred ARC) or between a tungsten alloy electrode and the job (transferred ARC). In this type of Lap Joint winding, there are three types of gas supplies being utilized Butt Joint namely plasma gas, shielding gas, and a back-purge gas. Tee Joint Plasma gas supplies throughout the nozzle turn into ionized. Edge Joint The shielding gas supplies throughout the external nozzle & Corner Joint protects the join from the environment. Back-Purge gas is mainly used when particular materials are being used. 1.2 PLASMA ARC WELDING 1.2.1 Equipment used in Plasma ARC Welding The PAW (Plasma arc welding) method is related to GTAW (gas tungsten arc welding). This arc can be formed The equipment used in the PAW includes the following. among the metal as well as an electrode. The major difference The power supply used in the PAW is a DC power among the PAW and GTAW is that in PAW, the welder is source, and the suitable voltage for this type of welding is capable in placing the electrode in the torch’s body; so this 70 volts otherwise above. will allow the PAW to be divided from the protecting gas. The typical welding parameters are voltage, current, and Afterward, the plasma is fed throughout a nozzle which will gas flow rate. These parameter values can be ranges like compress the arc to force the plasma away at high speed as the current is 500A, voltage is 30V to 250V, the speed of well as temperature. cutting is: 0.1 to7.5 m/min, the thickness of the plate is up to 200mm, required power is 2KW to 200KW, the rate of IJESC, March 2021 27824 http:// ijesc.org/ material removal is 150 cm3/min, and plas ma velocity is PAW is used to coating otherwise welding on the 500m/sec turbine blade. Current limiting resistors, as well as a high-frequency generator, are used for arc ignition. 1.3 MILD STEEL The plasma torch includes an electrode as well as water- cooling arrangement, and these are used to save the Conquest Steel & Alloys is one of the best nozzle & the electrode’s lifespan from dissolving due to manufacturer, supplier, and exporter of high quality industrial the extreme heat generated while welding. products. We are a popular trader, wholesaler of mild Steel The fixture is necessary to avoid atmospheric pollution Plates in all over the globe. We follow all standards and from the molten metal beneath bead. specifications and also in different types. We manufacture and Shielding gas is used for protecting the arc region from supply our product according to customer’s demand. The MS the atmosphere PLATES are available in different types, thicknesses, lengths, radius, dimensions, diameters, and many more. There are 1.2.2 Plasma ARC Welding Types different types of plates are available like polished, hot rolled and cold rolled plates, and so on. The plates are used in Plasma arc welding is classified into two types such as various industries because of good workability, formability, easy to fabricate, durability, easy to install, mach inability, 1) Transferred PAW weld ability, etc. The transferred PAW method uses direct polarity DC current. And in this method, the tungsten electrode can be MILD STEEL PLATE SPECIFICATION: allied to the –ve terminal and the metal can be allied to the +ve Thickness: 5mm-150mm terminal. The arc produces among tungsten electrode as well Width: 1000mm-4500mm as work portion. In this kind of method, both arc and plasma Length: 3000mm-18000mm moved toward the work portion, which will enhance the Process: Hot-Rolled (HR) heating capacity of the method. This type of PAW can be used to join solid sheets. Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12-2.0%.the American 2) Non-transferred PAW iron and steel institute (AISI) definition says. Steel is The Non-transferred PAW method used direct considered to be carbon steel when no minimum content is polarity DC current. And in this method the tungsten electrode specified or required for chromium, cobalt, molybdenum, can be connected to the –ve and the nozzle can be connected nickel niobium, titanium, tungsten, or any other element to be to the +ve pole. The arc generates among the nozzle as well as added to obtain a desired alloying effect. tungsten electrode within the torch, which will enhance the ionization of the gas within the torch. And the torch will 1.4 SWARM ALGORITHM transfer the ionized gas for further procedure. This type of PAW can be used to join thin sheets. Swarm intelligence is the discipline that deals with natural and artificial systems composed of many individuals 1.2.3 Advantages of PAW that coordinate using decentralized control and self- The advantages of PAW mainly include the following. organization. In particular, the discipline focuses on the Power consumption is low collective behaviors that result from the local interactions of Welding speed is high, so it can simply utilize to join the individuals with each other and with their environment. thick and hard work pieces. Examples of systems studied by swarm intelligence are Penetration rate and strong arc are high. colonies of ants and termites, schools of fish, flocks of birds, It can function at little amperage. herds of land animals. Some human artifacts also fall into the The arc arrangement doesn’t affect by the distance domain of swarm intelligence, notably some multi-robot among tool as well as the work piece. systems, and also certain computer programs that are written By using this method, the more steady arc can be to tackle optimization and data analysis problems. produced. 1.4.1 Taxonomy of Swarm Intelligence 1.2.4 Disadvantages of PAW The disadvantages of PAW mainly include the following. Swarm intelligence has a marked multidisciplinary The process is noisy. character since systems with the above mentioned Equipment cost is high. characteristics can be observed in a variety of domains. High expertise labor required. Research in swarm intelligence can be classified according to Radiation is more. different criteria. 1.2.5 Applications of PAW Natural vs. Artificial: It is customary to divide swarm The applications of PAW mainly include the following. intelligence research into two areas according to the nature of PAW can be used in industries like aerospace as well the systems under analysis. We speak therefore as marine of natural swarm intelligence research, where biological PAW is used to join stainless tubes and pipes systems are studied; and of artificial swarm intelligence, This type of welding is mostly applicable for where human artifacts are studied. electronic industries. PAW is mainly used to fix tools, mold and die. Scientific vs. Engineering: An alternative and somehow more informative classification of swarm intelligence research can be given based on the goals that are pursued: we can identify IJESC, March 2021 27825 http:// ijesc.org/ a scientific and an engineering stream. The goal of the the interactions among the individuals are based on scientific stream is to model swarm intelligence systems and simple behavioral rules that exploit only local information to single out and understand the mechanisms that allow a that the individuals exchange directly or via the system as a whole to behave in a coordinated way as a result environment (stigmergy); of local individual-individual and individual-environment the overall behaviour of the system results from the interactions.