ARC Welding:

A Popular Method:

Representing 20% of all robotic applications, arc welding is one of the most common functions in industry today. During this process, electricity jumps from an electrode guided through the seam, to the metal product. This electric arc generates intense heat, enough to melt the metal at the joint. Sometimes the electron is simply a conductor that guides the arc. Other times the rod or wire is composed to become part of the weld.

Creating a Fusion Bond:

The resulting fusion bond is a seamless addition to the product. The mix of metals has the same strength as the original metals. This is one of the reasons arc welding is preferred to soldering or brazing. Non-fusion methods can be weaker because they fail to duplicate the mechanical and physical properties of the metals.

Automated Arc Welding Benefits Include:

• Consistency of quality welds
• Repeatability
• Lowered production costs
• Fewer scrapped parts
• Increase your return on investment (ROI)
• 100% warranty
• Hands-on robot training
• Fewer injuries from weld splatter or fumes
• Speed - faster part cycle time

Arc, Spot Welding Techniques:

Welding has become an integral part of the lives of many people. Just like there are various different welding machines available, all the way from Diesel Welders to Pro-Arc's, there are also numerous welding techniques that can be used. In this article, we will cover some of the popular welding techniques like:

(1). Arc (2). Spot

Here, we will talk about why Arc welding is important. Arc welding is usually done by making use of a diesel welder. In arc welding, high electric voltage is used, instead of a gas torch. The arc, or the spark, created from the electrode rod, used by the welder, is transferred from one metal to the other metal. This in turn causes the metals to heat up and melt together which creates a bond or a weld amongst them. Arc welding is known to create cleaner, smoother, accurate and stronger welds.

The second technique to be discussed is the Spot technique. In this method, the two metal sheets are held together tightly by the electrodes. The surface area of contact between the electrodes and the materials is very small, and hence it is called 'spot' welding. When a large amount of current is passed through the electrodes, it heats up the spots to the point of melting, which results in a sturdy weld. This technique ensures that the rest of the metal isn't heated up unnecessarily and also takes lesser time.

Advantages of SAW (Submerged Arc Welding):

-It has a high deposition rate and it can penetrate the weld deeply.

-When you have designed a good process and you have control over what you are doing you can be sure that you get a strong weld.

-You can actually do this with thin sheets of steel and they can be done at a higher speed.

-There are very minimal fumes or arc lights which makes this a safer process.

-You can do this indoors or outdoors.

-You don't have a lot of distortion.

-You don't get any spatter on the weld because the arc is always under the blanket of flux.

-As with any technique there are a few limitations with the SAW method that include:

-You are limited to only a few positions that you can use this within.

-You can only use steel, stainless steel or a few nickel based metals.

-The flux handling systems can be more complex and difficult to use.

-Slag is a problem in a couple of ways: you can get residue from it that may cause some issues with your health or with safety and it will require a complicated slag removal system.

Short note on Basic arc Welding Circuit:

The fundamental arc-welding circuit is demonstrating in the image. An AC or DC power source, fixed with whatever controls may be wanted, is linked by a work wire to the work piece and by a "hot" cable to an electrode controller of a few type, which makes an electrical contact by the welding electrode.

An arc is formed across the gap when the energized circuit and the electrode tip touches the work part and is withdrawn, yet still with in close contact.

The arc creates a heat of about 6500ºF at the tip. This high temperature melts together the base metal and the welding electrode; creating a pool of molten metal sometimes called a "crater." The crater solidifies behind the electrode as it is moved along the joint. The outcome is a fusion bond.

Submerged Arc Welding overview:

Submerged arc welding is a small different than most other forms of welding since the arc and the end of the electrode are not able to be seen to the operator. Both are kept below a pile of grainy flux. The majority ordinary use for this welding scheme is by machines, but there are semi automatic versions. The machine is used to start the arc and gives the electrode by feeding it to the weld region from approximately a spool. The flux is in a granule form and is dispersed in front of the weld pathway. The scheme is able to also be set up with two electrodes positioned vertically side by side, vertically one in frontage and one in backside, or in a v-shaped to speed the procedure up. Some of the flux is melted in the welding process which generates a slag that helps guard the weld from the surroundings and from cooling. A few joints up to 3" wide are able to be welded in one pass. This technique is regularly done in a flat position and is great for ships and bridges where extended welds are wanted.

The slag in this situation helps to generate a clean and strong weld. With the arc enclosed up, spatter and heat loss into the nearby surroundings is not a trouble. Alloy and metal powders are able to be added to the flux grains in order to assist fill the seam. Not a lot of smoke is created if any and no defense is wanted to shield from the light from an arc. The system is automatic simply and there is not a lot of talent wanted for the procedure. The slag generated limits submerged arc welding to simply to a flat position. The heat that is generated by the weld stays in the metal longer due to the flux covering which can boost distortion of the metals.

Significance of Welding Machines and its Contributors

This can be very significant to check out the several types of equipment supplier that's out present. Most of them are centered on remarkable offers and more. It will get relevant to find the most useful types of welding machine supplies and much more.

All essential machines have to be targeted upon and that is very important to getting exciting offers. Wonderful provides are put forward and finest varieties of welding supplies be certain that people get amazing offers and more. This may be appeared into if someone needs to get welding equipment.

Welding equipment is associated for a complete lot of reasons. Mainly as a result of it becomes important to get wonderful offers which all clients have a tendency to like a lot. It's required to take a look at the various kinds of work this welding machine provides trust to achieve.

The profits of a Welding Career

Welding is an important skill because people's lives can depend on a metal construction to be strong and last for many years.

A certificate earned during a welding training list can prove to potential employers that they can count on you to possess the skills required to do high quality welds.

Here are a few machines you can function through hands-on experience:
• Electric Arc Welder
• Automatic Pipe Bevel
• Flux Core Arc Welders
• Hand-Operated Grinders

The welding preparation programs offer a range of certifications through professional schools in your area.

You can get the welding skills that are in demand by employers in as rapid as 40 weeks.
Attaining a high quality welding career will help guide to a very successful, and beneficial, career!

Features Found on Mig & Tig Welders

Mig Welding Equipment
Ranging in size from a small, convenient 115v, 20 amp machine to full sized shop automotive service equipment, mig welders are one of the few that unite a relatively low cost tag with high quality performance. You can also gain full control over the quality of the weld with a full variety of settings. Finally, these machines turn up with added benefits such as colder running temperatures and some of the best guarantee options.

Tig Welders
Even the most essential tig welding machines move toward loaded full of features. Press on button control panels create them easier to use while advanced end models let you easily adjust the machines repeatable weld cycles, start, and weld hollow. To modify the shape and size of the bead, look for models with true square wave AC output and pulse style. Finally, look for models with further safety features such as warning code circuitry and voltage protection.

TIG Welding:

TIG welders are intended for the Gas Tungsten Arc Welding method (GTAW), which is usually referred to as the Tungsten Inert Gas method (TIG welding). The TIG method derives the warmth for welding as of an electric arc recognized among a non-consumable tungsten electrode and the division to be welded. Filler metal, if used, is physically provided for into the weld puddle at what time TIG welding.

The TIG welding method requires an air- or water-cooled torch to hold the tungsten electrode and is linked to the TIG welder. The TIG welding method also requires an outside defensive gas, characteristically argon, helium, or a combination of the two to defend the melt metal and electrode from impressive contagion.

High excellence welds can be created by TIG welders. The TIG welding method too has all places welding ability and is brilliant on extremely thin equipment. In addition, a TIG welder makes welds that contain exceptional look and clean-up is quick and simple as there is no slag and fundamentally no splash.

IMPACT OF ENGINEERING CONCEPTS IN WELDING

What is engineering? Engineering is a discipline where we apply technical, scientific and mathematical knowledge to implement and to design some machines, devices and structures. The power equipments and machines we use in the welding industry are the inventions of engineering concepts. Plasma cutter the equipment which cuts different types of metals has the in built structure which is made of electrical components and the electrical energy is converted in mechanical energy during the operation of the machine. All other welding products such as mig, tig, wire feeders and water coolers are the child of engineering concepts. Silent diesel generators the alternative source of power supply is also an invention of engineering concepts. In generators the electrical energy is converted into mechanical energy. In welding torches the gas which flows is controlled by a gas valves is a mechanical engineering concept which follows some mechanics.

Arc welding process and its equipments

Welding is regularly used for the permutation processes i.e. arc, resistance, laser, electron beam, stud and orbital welding.

Weld controllers are necessary to help the processes used by these tools. Welding equipments also work as aid to welding control source. There are also wide-ranging system to cutting machine, torch, feeders, cables, robots and feeders.

Arc welding process and welding machines

Arc welding is utilizing welding power supply to produce an electric arc between the base material and an electrode, for melting the metals at welding point. Arc welding equipments can use and direct current or alternating current, and consumable or non-consumable electrodes. Shielding gas guards welding region using some inert or semi-inert gas and evaporate wadding material. The process of arc welding is broadly known for low capital and running costs.

MIG and TIG welding are the two common specifications of Arc Welding. MIG is also acronym as MAG (metal active gas welding) and known as one of the mostly popular arc welding process. MIG welding equipments uses in different kinds of gas like pure carbon dioxide, argon gas and some time merge of both to complete the process.

Learn how to know about Arc Weld and Stick Weld

All we have to follow a few steps, to obtain that welding down part:

There are a few basic and simple to learn steps to facilitate you need to take into consideration before you even try how to stick weld or arc weld.

How do I know? I've been present and done that. I know how hard it be able to learn how to stick weld for a person who has never welded before in their life. Regularly the first timer will make a few silly mistakes that can destroy their first time stick or arc welding experience

Equipment like:

• How to strike an arc and remain it going. This is a big subject for anyone who is learning how to stick weld. How can I do it? Why does it remain sticking to the job?

• What range welding electrode should I use?

• What kind of welding electrode should I use?

• Which method do I move the electrode?

• What power setting should I set my machine on?

What about welding protection. What should I be alert of when welding? What will harm me and put me at risk of injury? If you are new to welding, you might not be attentive of what to look out for.

Electric Arc Welding

An electric arc welder is essentially a low voltage, high amperage power source. It has a cable connection to the handpiece and another cable connection to the project itself. The handpiece holds an electrode which, when tapped against the work, produces a high temperature arc at the electrode tip. This heat is sufficient to melt the tip of the electrode which falls into the weld joint forming a bead as it cools. A flux is necessary and the heat causes the flux to form a gas shield around the weld area. As the electrode is consumed the operator alters the position of the handpiece both to follow the joint and to keep a constant arc gap. Adjustments on the welder itself allow the operator to use a variety of welding rods depending on the nature and composition of the weld required.

Electric arc welders are often portable devices allowing welding to be carried out in the field as required. This is useful on farm applications, mining, pipelines and other outdoor situations. Manual electric arc welding, or stick welding as it is often known, is the most common joining method involving heat that is employed with steel.

Welding Procedure

Assembling the Torch
Select the proper diameter electrode by consulting this document’s Appendix. It is necessary to properly prepare the electrode tip in order to get a good weld. If DC welding is to be performed, the tip must be sharpened much like a pencil. The easiest way to do this is to use the band-sanders in the foundry. Turn on the sander, hold the electrode at about a 20° angle to the sander face, and rotate the electrode until a sharp point is formed. If AC welding is to be performed, a rounded, conical tip is necessary. In order to properly shape an electrode for AC welding, first sharpen it as one would for DC welding. The second half of the AC electrode preparation will be discussed later, after the rest of the equipment is up and running.

Select a collet that is the same size as your electrode. The collets are often not in their proper bins, so double-check to see that it slides snugly around the electrode. Pick a cup with an appropriate orifice diameter to match the electrode (see Appendix). Screw the lens into the back of the torch, and then the cup over the lens from the front. Slide the collet around the electrode and slip the electrode through the lens and out the front of the torch. Then screw the electrode cap onto the back of the torch, thereby, covering the back of the electrode and locking it into place. The electrode should protrude between 1/8 and 1/4 of an inch out of the front of the torch. If it sticks too far out, loosen the cap and adjust it until it is in the appropriate position.

Grounding the Workpiece

One must make sure that electricity can properly flow out of the workpiece to ground. First, securely clamp the grounding cable to the welding table. Second, fixture the workpiece in a manner so that there is direct contact between the workpiece and the table.

Turning on the Equipment


First of all, check to see that the cooling water valve to the right of the welding machine is fully open (it should always be left open for safety’s sake). Then flip the main switch on the front of the welding machine to the ON position. Next, open the regulator valve on the top of the argon tank. It is a "double seating" valve which must opened all the way in order to properly seal.

It is usually a good idea to check that both the argon and the water are flowing properly. In order to do this, hold the torch in one hand so that it is not in contact with any metal and press down on the foot controller. This should start both the argon and the water flow. On the 300, you can look out the window behind the machine to see that the water is exiting the machine through the disposal tube. Check the flow meter on the argon regulator to see that the argon is flowing at the proper level. (See Appendix for suggested flow rates) Adjust the flow meter if necessary.

Joint Preparation

Proper cleaning of the metal can be essential in producing a solid joint. This is especially true with aluminum, where the pieces to be welded should always be scrubbed clean of all corrosion and dirt. Steel can usually be left as is, unless the pieces are extremely corroded.

Fixture the pieces to be welded in a fashion that allows for proper current flow between the workpiece and the table. Pieces usually do not have to be clamped together, but they should be well supported.

Protection


The arc produced in TIG welding gives off very dangerous UV radiation. Even if one is to catch only a slight glimpse of the arc with the naked eye, one can expect to have a headache the next day. It is the responsibility of the welder to look after his/her own safety and the safety of others.

First, always set up the orange screens around the two edges of the welding table that face the rest of the room. These are crucial in protecting others. Next be sure that there is no exposed skin on the body of the welder. Wear the TIG welding gloves to protect one's hands and be sure that one is wearing only natural fabrics, since synthetics could melt if exposed to sparks from the welding. It is also a good idea to wear either a turtle neck or a shirt with the neck buttoned in order to be sure that one's neck is not exposed. Any unprotected skin can receive a nasty sunburn from overexposure.

Next, put on an arc-welding helmet. Keep it in the upright position on your head until you actually weld. The one with the large smoked glass plate in the front provides a better field of vision than the others with smaller plates. The darkness of the glass is rated from 1 to 15. Be sure that the glass in your helmet is 11 or over.

Preparing to Weld

Sit at the welding table with your properly fixtured workpiece in front of you. Place the foot controller in front of your chair so that you can comfortably control it with your foot. Hold the properly assembled torch in the hand that you write with. Grasp it about half way along the shaft that connects to the hoses in the same manner as you would grip a pencil. Hold a piece of filler rod in your other hand if you intend to use it.

Starting the Arc

Since the welding machine features a high frequency start current, it is not necessary to make contact with the workpiece in order to start the arc. So place the torch at the point where you wish to begin the weld about with the tip of the electrode about 1/8” off the workpiece. Then lower the visor on the welding helmet. You will not be able to see anything until the arc has started. Call out “welding” so that everyone else in the room knows to avoid looking at the arc. Press down nearly all the way on the foot switch and the arc should start. If it does not start (because you are too far away) slowly bring the electrode tip closer to the workpiece until the arc forms. Do not make contact with the workpiece as this can melt the electrode! The light of the arc should illuminate as small area around the torch so that you can see.

A common problem is to have the torch stray away from the intended starting position when the visor is lowered. A good trick in avoiding this is to actually touch the electrode to the intended starting point on the workpiece before lowering the visor. This will usually anchor the electrode enough so that it will not move when the visor is lowered. Then, bring the electrode slightly off the workpiece but keep it within 1/8” so that the arc will still start. Then press down on the foot controller to start the arc.

Source: http://www.stanford.edu/group/prl/documents/html/TIGweld.htm

Magnetic Rotating Arc Welding

Developed in the 1970's, magnetic rotating arc welding is also known as magnetarc welding or magnetically impelled arc butt (MIAB) welding . It is defined as "an arc welding process in which an arc is created between the butted ends of tubes and propelled around the weld joint by a magnetic field, followed by an upsetting operation." The procedure is a mixture of arc and forge welding with a gas shielding operation added on. This method of welding by clamping the parts to be joined into the machine. Next, the two pieces are pushed together and electricity is applied to them. As they are separated, an arc is started. When the arc is established, a magnetic coil around the weld repels the arc, which pushes it around the perimeter of the piece. The arc runs around the piece at a speed close to 50 meters a second. At this speed the arc looks as though it is a circle of light between the pieces. After the arc has run around the piece for a determined amount of time, the two pieces are pressed together to join them .

This process is now very popular in mass production situations. The entire system is fast, can be automated, and requires less energy than other types of welding. The parts do not need to be cylindrical and the welds are repeatable with high quality and little deformities. Also, this welding does not expel as much metal as does other forms of welding, which makes MIAB welding more efficient. The drawback comes from the fact that the arc only heats the edges of the pieces, not the middle. This means that only a certain thickness of metal can be welded in this fashion and that solid pieces of metal cannot be joined.

Arc Welding and Related Methods

Atomic Hydrogen Welding

This process involves injecting hydrogen into extreme heat in the arc, the temperature makes the hydrogen gas (H2) and breaks it down into its simplest form, which would be two hydrogen atoms. The arc is formed between two tungsten electrodes, not between the metal workpiece and the electrodes as in other types of arc welding. This process absorbs energy away from the arc, but gives it back as the hydrogen recombines as it contacts the metal work surface. The procedure uses the heat from the reaction to heat the metal. The temperature of the flame reaches 3700°C and can then be used for welding . The arc in this case does not have much of an effect on the weld except it can increase the temperature some as the electrodes get closer to the weld pool. The transformer for this operation is generally around 300 volts, so caution is needed.

For years hydrogen arc welding was used for hard-to-weld metals such as nickel-base alloys and high alloy steels. The hydrogen used helped reduce gas bubbles in the weld, which provided a seam with fewer pores. This makes a much stronger weld because more metal is holding the pieces together. The hydrogen is also good due to the fact that other gases cannot enter the weld pool because it is protected by the stream of hydrogen gas. This process has been almost overshadowed by inert-gas arc welding.