Gas Metal Arc Welding Basics: Travel Speed and Contact to Work Distance (CTWD) June 30, 2015. In the field,time is money. These gases protect the weld form other reactive gases which can damage the strength of welding joint. This video is used by many welding schools and shops across the world as an introduction and refresher to mig welding basics. Our subcontractor was going bankrupt paying big bucks for stainless steel electrodes the process required. Metal Inert Gas (MIG) welding was first patented in the USA in 1949 for welding aluminium. - - - This electrode travels continuously on welding area for making proper weld joint. One of the amazing aspects of welding is that even a novice welder can experience some success. Futures: at least 10 minute delayed. Gas metal arc welding (GMAW), or Metal Inert Gas (MIG) welding was first patented in the USA in 1949 for welding aluminium. MIG is an attractive alternative to MMA, offering high deposition rates and high productivity. As I mentioned on an earlier web post, I bought several of Steve Bleile's welding videos and this one, Mig (GMAW) welding, Is a knockout. Using electrodes requires chipping and brushing each bead, which can take quite some time when you're welding thousands of feet. Welding roughly between 0° — 15° pushing or pulling (facing towards or away from your travel direction) is the ideal range to choose from. (my travel speed was 7 inchs per minute) How much travel speed should I have in mig welding? And they control the direction and speed of welding travel through their skill. The molten metal at the tip of the wire transfers to the weld pool in the form of a spray of small droplets (about the diameter of the wire and smaller). All Rights Reserved. The arc and weld pool formed using a bare wire electrode was protected by helium gas, readily available at that time. The tendency for me was left to right but maybe that was how I started with stick. Welding technique. MIG welders are where the wire, the gas, and the electricity combine to deliver a weld via the welding gun. However, there is a minimum current level, threshold, below which droplets are not forcibly projected across the arc. Going left to right (backhand) seems to have a more stable arc and there is less splatter. The arc and weld pool formed using a bare wire electrode was protected by helium gas, readily available at that time. MIG Welding study guide by Domkane8840 includes 81 questions covering vocabulary, terms and more. ), but... read more. I realized that my farmâs service truck had all the tooling my shop had (a welder, torch, fuel supply, air, chop saws, grinders, etc. Reference(s): Travel Angle: the degree of the travel angle, whether a push or drag travel angle, affects how much of the arc force is directed down into the base plate. Work angle is “the relationship between the axis of the electrode to the welders work piece.” Travel angle refers to employing either a push angle (pointing in the direction of travel) or a drag angle, when the electrode is pointed opposite of travel. It is a process developed in the 1940's, and is considered semi-automated. Introduction In the first blog of this series, a general description was given of the basic operation of the gas metal arc welding (GMAW) process. The decision was made to switch to MIG welding, which reduces waste, such as incompletely burned electrodes, and requires little to no cleanup. What is a MIG welder? Always keep it to a tight stringer beads on any joint. MIG welding is referred to as a semi-automatic welding process owing to the fact that the rate at which the wire is fed and the length of the arc are controlled by a power source, but the speed of travel and the position of the wire are controlled manually. The MIG gun should be pointing upward between 35 to 45 degrees and tilting about 15 to 35 degrees toward the direction of the weld. Care in setting the voltage and the inductance in relation to the wire feed speed is essential to minimise spatter. When MIG welding mild steel, you can use either the push or pull technique, but note that pushing usually offers a better view and enables you to better direct wire into the joint. MIG is similar to MMA in that heat for welding is produced by forming an arc between a metal electrode and the workpiece; the electrode melts to form the weld bead. With stick welding, look to keep that distance ⅛ inch between the rod tip and work piece. Read on for tips on how to MIG … If the weld had been done at lower amps and a slower travel speed to compensate the heat affected zone would have been much wider. For dutch people, look on NIL - Nederlands Instituut voor Lastechniek, Microbiologically Induced Corrosion (MIC), Differences between Castings and Forgings, Differences between Cast Iron and Cast Steel, Fireproofing for Petrochemical facilities, Standards defined on this website (19 pages), Dimensions Across Flats and Heights of Hex Nuts, Introduction to air-cooled heat exchangers, Image presentation Hot tapping and Line stopping, North Transgas and North European Gas Pipeline (10 Pages), stabilises the arc roots on the material surface, ensures smooth transfer of molten droplets from the wire to the weld pool. The angle of the MIG gun should be pointed up between 35 to 45 degrees and you should lean toward the direction of travel up to 35 degrees. Travel angles beyond 20 to 25 degrees can lead to more spatter, less penetration and general arc instability. MIG welding of aluminum progresses at a faster travel rate than for steel. All https://www.barchart.com/solutions/ is provided by Barchart Solutions. In the photograph it is quite narrow, maybe 15mm edge to edge. The main differences are that the metal electrode is a small diameter wire fed from a spool and an externally supplied shielding gas is necessary. TWI - World Centre for Materials Joining Technology (there you can find a lot of information about welding). Learn what direction of travel is in welding from an expert in arc, tig and mig welding … General purpose shielding gases for MIG welding are mixtures of argon, oxygen and CO2, and special gas mixtures may contain helium. MIG is widely used in most industry sectors and accounts for more than 50% of all weld metal deposited. MIG welding uses an arc of electricity to create a short circuit between a continuously fed anode (+ the wire-fed welding gun) and a cathode ( - the metal being welded). For droplet or spray transfer, a much higher voltage is necessary to ensure that the wire does not make contact i.e.short-circuit, with the weld pool; for a 1.2mm diameter wire, the arc voltage varies from approximately 27V (250A) to 35V (400A). A look at Kubota's L60LE compact tractors, A look back on 55 years of National Farm Machinery Show, Vise attachment for hitch completes a shop on wheels. I think it might penetrate better too. In MIG/MAG/TIG, the angle of the torch with respect to the direction of travel has a significant influence on the shape of the welding bath and the penetration level that can be achieved. Operate on the Right Travel Speed. The welding torch is feeding the wire in the same direction as the direction of travel. ... the travel angle when the electrode is pointing away from the direction of travel. MIG welding is an abbreviation for Metal Inert Gas Welding. MIG welding also eliminates slag inclusion (slag in the weld) and reduces restarts that can caus… Fillet weld leg. Avoid holding the electrode close to the vertical plate when you want to make horizontal fillet welds. The core tool is the welding MIG machine. Gas metal arc welding (GMAW), sometimes referred to by its subtypes metal inert gas (MIG) welding or metal active gas (MAG) welding, is a welding process in which an electric arc forms between a consumable MIG wire electrode and the workpiece metal(s), which heats the workpiece metal(s), causing them to melt and join. In order to see the joint and puddle, the welder may tip the rod up to 10 degrees in the direction of travel, or sometimes against the direction of travel. Due to the high thermal conductivity and low melting point of aluminum, the travel speed will increase as the welding progresses. If an open arc technique is attempted much below the threshold current level, the low arc forces would be insufficient to prevent large droplets forming at the tip of the wire. Arc spacing: Adjust travel speed so that the welding arc stays within the leading one third of the weld pool. However, there is a greater risk of lack of fusion defects because these gases are colder. Normal welding conditions in all positions call for a travel angle of 5 to 15 degrees. Work angle The second angle used in welding is the travel angle. A travel angle of 0° to 10° (i.e., the electrode perpendicular or mostly perpendicular to the plate) will result in more weld penetration. © 2020 Meredith Corporation. I've welded both ways. Most travel speeds for various joints are well below 40 inches a minute. However, when welding aluminum, there are a few important factors that the welder needs to keep in mind, as there are certain differences from welding steel. Travel angle. Metal transfer is achieved by applying pulses of current, each pulse having sufficient force to detach a droplet. As the wire is continuously fed, the process is often referred to as semi-automatic welding. Always keep track of the amount of weave used and observe the weld speed. The only manual controls required of the welder for semi-automatic operation are travel speed, travel direction and gun (torch) positioning. In addition to general shielding of the arc and the weld pool, the shielding gas performs a number of important functions: Thus, the shielding gas will have a substantial effect on the stability of the arc and metal transfer and the behaviour of the weld pool, in particular, its penetration. MIG welding was developed in the 1940's and 60 years later the general principle is still very much the same. Direction of Travel in Welding. Inductance is used to control the surge in current which occurs when the wire dips into the weld pool. The travel speed can be judged by the width of the heat affected zone around the weld (the discoloured part). However, it should be noted that while MIG is ideal for "squirting" metal, a high degree of manipulative skill is demanded of the welder. CO2 & argon CO2 mixtures are known as metal active gas (MAG) processes. However, Karl Hoes of Lincoln Electric and John Leisner of Miller Electric caution that there are some hard-and-fast rules to produce a lasting welding repair. below the threshold level, to avoid short-circuiting and spatter. Gas metal arc welding (GMAW), or Metal Inert Gas (MIG) welding was first patented in the USA in 1949 for welding aluminium. I think in this weld my travel speed is not correct, what do u think ? Travel angle is defined as the angle relative to the gun in a perpendicular position within the plane of the weld joint. Horizontal welding is a little harder. There are three principal metal transfer modes: Short-circuiting and pulsed metal transfer are used for low current operation while spray metal transfer is only used with high welding currents. MIG Welding Machine: How It Works Image of an example of a MIG welding machine along with its necessary equipment except for gas cylinder. The speed of travel must be constant to attain a satisfactory weld size. Synergic pulsed MIG refers to a special type of controller which enables the power source to be tuned (pulse parameters) for the wire composition and diameter, and the pulse frequency to be set the wire feed speed. Part of the series: Welding Basics: Techniques for Tig, Mig & Arc Welds. For related content and insights from industry experts, sign up for Successful Farming newsletters. If travel speed is not increased, there is a chance of excessive melt-through on thin aluminum parts. To get up to speed please look at … The pulsed mode was developed as a means of stabilising the open arc at low current levels i.e. Figure 9: Different angles of the torch With MIG the right to left method is usually faster (forehand technique). The angle of the direction of travel should be kept between 10-15 degree. MIG welders are versatile systems designed to handle a wide variety of projects, including welding aluminum. These droplets would transfer erratically across the arc under normal gravitational forces. As CO1 cannot be used in the open arc (pulsed or spray transfer) modes due to high back-plasma forces, argon based gases containing oxygen or CO2 are normally employed. From about 1952 the process became popular in the UK for welding aluminium using argon as the shielding gas, and for carbon steels using CO2. Information is provided 'as is' and solely for informational purposes, not for trading purposes or advice. MIG is an attractive alternative to MMA… From about 1952 the process became popular in the UK for welding aluminium using argon as the shielding gas, and for carbon steels using CO2. In short-circuiting or"dip" transfer, the molten metal forming on the tip of the wire is transferred by the wire dipping into the weld pool. Steve Bleile’s mig welding video - gas metal arc welding. MIG Welding and the right Crackle. For wire (flux-core or MIG) welding, keep a work distance of ⅜ to ½ inch. The semi automatic part is the human welder directing the MIG gun, using their skill to position the gun the right distance and angle from the joint. Torch position is also very important. Given proper equipment settings, the power supply will provide the necessary amperage to melt the electrode at the rate required to … This means that the welder still requires skill, but that the MIG welding machine will continuously keep filling the joint being welded and electrodes do not need to be changed out between welds. The best technique … (AWS Welding HandBook 9th Edition Vol 2 Page 184) 2. Go for a Multi-Run Weld Technique To see all exchange delays and terms of use, please see https://www.barchart.com/solutions/terms. The gases which are normally used for the various materials are: Argon based gases, compared with CO2, are generally more tolerant to parameter settings and generate lower spatter levels with the dip transfer mode. The arc and weld pool formed using a bare wire electrode was protected by helium gas, readily available at that time. Backhand Welding The welding torch is feeding the wire in the opposite the direction of travel. Flat position When welding a butt joint (a 180-degree joint), the welding operator should hold the MIG … This arc is well shielded by shielding gases. The human welder also develops the skill of listening for the right crackle. CO2 & argon CO2mixtures are known as metal active gas (MAG) processes. You need to watch out for overlap and the weld rolling over. This is achieved by setting a low voltage; for a 1.2mm diameter wire, arc voltage varies from about 17V (100A) to 22V (200A). Travel angle Normal welding conditions in all positions call for a travel angle of 5 to 15 degrees. This is the relationship between the torch and line of travel. Compared to MMA, MIG has the advantage in terms of flexibility, deposition rates and suitability for mechanisation. The arc length should be kept at approximately 5mm from the weld pool. Travel speed is an important consideration when welding. (Sorry for silly questions, i am new to welding) I will glad to know ur comments about my weld in overall. 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