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.

Flux-Core Arc Welders:

Flux-Core Arc Welders use a wire that, in its core, contains materials that release the shielding gases necessary to be able to protect the molten metal from the environment. There is no need concerning any external shielding agent, and also the shielding gases released by the wire can even withstand powerful breezes.

The drawback to the Flux-Core Arc Welders is that they use a fairly forceful arc, creating a large amount of spatter. Additionally, there can end up being slag on the final welding job, as well as it's going to end up being removed for a neat, clean finish. Extra disadvantages can appear as a result of mechanical troubles, like irregularity in the wire feeding. The filler material will be also a lot more costly than that compared to a Gas-Metal Welders.

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.

Welding & Cutting Safety Tips:

Cutting and welding of metals involve the application of high temperature to the things being welded or cut. This powerful high temperature is obtained from the use of inflammable gases, (ex., acetylene, hydrogen, etc.) or electrical energy. The intense welding warmth and the sources employed to create it can be potentially dangerous.

Therefore, to guard persons from damage and to guard building and gear against flames, etc., a set of advices about safety and health actions for the welders and those worried with the safety of the tools, etc., have been published by ISI and several other similar but International organizations.

By keeping in mind the following suggestions or precautions, the risks linked with welding can be mostly reduced. So, it is recommended that the beginner in the field of welding have to go through and become well-known with these suggestions which also have been discussed below:

1). Security advices for installation and operation of Gas welding and cutting tools.
2). Security advices for installation and operation of Arc welding and cutting gear.
3). Explosion, fire and additional hazards and defense against them.
4). Protection of welders.
5). Ventilation and health safety.

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.

How to Improve TIG Welding Efficiency:

By its very nature, TIG welding is a comparatively slow process. But it is too a very adaptable one. In fact, it can be used to weld many materials than any other welding process, even exotic and heavier alloyed metals. It is too ideal for slim resources, as it generates a low heat input to prevent burn-through. Plus, no matter the application, when completed correctly TIG welding can give very high weld excellence.

Achieving such positive results, though, isn’t forever easy-it as much a matter of training and do as it is easy patience. Luckily, arming yourself with few tips along the way can help you very much get better the competence of the process. After all, you don’t want an already slow welding process to turn into slower!

Top Five Tips for Improving TIG Welding Efficiency:

>> Invert the Process

>> Stay Cool and Flexible

>> Cover Yourself

>> Less Can Be More

>> Get to the Point

Final Tips:
Keep in mind, no welding process is perfect. Still, with a few know how and a bit of practice, it can become additional efficient-even if you are using a comparatively slow process similar to TIG welding. The key is to create sound decisions about your gear selection and take care with the size of the welds you are completing. Ultimately, taking that little bit of time upfront can save you time and money in the long run.

Safety Tips for Welding:

There are some rules you should follow as you are welding/hard facing:

• Protect yourself from fumes and gases - for all time weld in an open, fine ventilated space and stay your head away of the fumes, particularly by hard facing.

• Dressed in protective clothing - Protect your eyes and face with a welding helmet designed for arc welding, not simply gas welding safety glasses. In the similar way, guard your body from weld spatter and arc flash with woolen or cotton clothes, a fireproof apron and gloves, and boots. In addition make sure to protect others nearby you from the arc rays as well.

• Beware of electric shock – Don’t touch exist electrical parts and make sure to your welding machine is correctly grounded. In no way weld if you are wet or if your gloves contain holes in them.

• Fire/explosion hazard - In no way weld in an with this space or close to hay, feed bags, gasoline, diesel, hydraulic fluids or something else that can be inside the reach of your welding sparks that would cause a fire or explosion. Not at all weld single handedly. Forever have a buddy close in case of an emergency.

Basics of Stick Welding:

Stick, the majority basic of welding processes, offers the easiest selection for combining steel and any other metals. Stick welding power sources deliver inexpensive choice for welding versatility, portability and reliability. Stick welding connects metals when an arc is struck between the electrode and the work part, creating a weld pool and depositing a consumable metal electrode into the joint. The electrode's protecting coating also acts as a shielding gas, protecting the weld and ensuring its cleanliness and power. Most excellent for windy circumstances and unfavorable environments.

Shellfish is able to create you a best welder. Just think about CLAMS: Current setting, Length of arc, Angle of electrode, Manipulation of the electrode and Speed of travel. If you are just learn the Stick welding process, technically called Shielded Metal Arc Welding, remembering these five points will improve your welding technique.

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.

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.

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.

What Does a Metal Fabricator/Welder Do?

A metal fabricator has to be talented to interpret engineering drawings and then exactly cut steel plates into the required shapes. They must then weld them into the structure according to the drawings.

Metal Fabricators must learn to read engineering drawings, use geometric progress methods and metal forming techniques. They must also be able to use computers in making metal products, and have a inclusive knowledge of a range of industrial welding and joining processes to produce the required items.

Welding Tragedies

Personal Protection While Welding

It is necessary that the worker and helpers be properly clothed and protected because of the heat, ultra-violet rays, and sparks, produced by the arc welder. For body protection a pair of fire retardant long sleeved coveralls without manacles is a good choice. Always avoid clothing with tears, snags, rips, or worn spots as these are effortlessly ignited by sparks. The sleeves and collars should be kept buttoned. The hands should be confined with leather gauntlet gloves. A pair o high top leather shoes, rather safety shoes, is good defense for the feet. If low shoes are worn the ankles should be protected by fire opposed to leggings. Eyes should be protected by translucent spectacles if the person wears recommendation glasses or safety glasses if not. A welding helmet or hand shield with filter plate and cover plate is mandatory for eye defense from the harmful rays of the arc. The filter plate should be at least shade for common welding up to 200 amps. However, certain operations such as carbon-arc welding and higher current welding operations need darker shades. Never use a helmet if the riddle plate or cover lens is cracked or broken. A flame-proof skull cap to protect the hair and head as well as hearing shield in noisy situations is recommended.

Plastic throwaway cigarette lighters are very dangerous around heat and fire. It is very imperative that they not be carried in the pockets while welding. Always provide protection to bystanders or other workers by welding inside a appropriately screened area, if possible. If powerless to work inside a screened area then protection to others should be provided by a transferable screen or shield, or by their wearing anti-flash goggles

Arc-Welders

All arc welding and cutting cables shall be of the completely insulated, flexible type, capable of handling the maximum current requirements of the work in progress, taking into account the duty cycle under which the Arc welder or cutters is working.

Any current-carrying parts passing through the portion of the holder which the Arc welder or cutter grips in his hand, and the outer surfaces of the jaws of the holder, shall be fully insulated against the maximum voltage encountered to ground.

Only cable free from repair or splices for a minimum distance of 10 feet from the cable end to which the electrode holder is connected shall be used, except that cables with standard insulated connectors or with splices whose insulating quality is equal to that of the cable are permitted.

Projection Welder -Seam Welder

Gas Welders:

Make the weld by guiding the arc, with its intense heat, along the edges of the metals to be joinedSelect proper types of welding torch tip according to the metal and the job being done.

* Gas welding torches
* Gas shielded arc equipment
* Arc welding torches
* Blueprints and templates
* Submerged arc welding equipment
* Clamps and calipers
* Rules, squares, and hand tools

You Should Prefer:

•ARC WELDERS join metal parts using electric Arc welding equipment.
•PRODUCTION LINE WELDERS join metal parts on production lines, using pipes lines or gas equipments.
•GAS WELDERS join metal parts together using gas Welding equipment and combine their own techniques in the parts .
•EXPERIMENTAL WELDERS analyze engineering data and weld experimental parts to determine the most effective welding process, using various Welding methods and Equipment.

Standard Features:

The work of arc, plasma, and flame cutters is closely related to that of welders. However, instead of joining metals, cutters use the heat from burning gases or an electric arc to cut and trim metal objects to specific dimensions.

Cutters also dismantle large objects, such as ships, railroad cars, automobiles or aircraft. Some operate and monitor cutting machines similar to those used by welding machine operators.

Welders often work in a variety of awkward positions, having to make welds while bending, stooping, or working overhead. In some settings, however, working conditions are much better and there are few hazards or discomforts. Overtime is sometimes necessary to complete special projects.

Occupational Exposure Limits for Manganese

Agency : Occupational Exposure Limit
NIOSH REL : 1 mg/m3 (TWA) and 3 mg/m3 (STEL)
NIOSH IDLH : 500 mg/m3
OSHA PEL : 5 mg/m3 (ceiling)
ACGIH TLV : 0.2 mg/m
IDLH: immediately dangerous to life and health concentration
PEL : permissible exposure limit
REL : recommended exposure limit
STEL: short-term exposure limit
TLV : threshold limit value
TWA : time-weighted

Equipments Used By Welding Process:

* Servicing and installation must only be undertaken by a qualified licensed electrician. Never tamper with electrical supply circuits or systems. The welder is only responsible for making connections in the welding circuit and for setting external welding machine controls.

* Equipment should be well maintained and checked regularly, particularly the insulation and connections on work return leads and holders.

* Electrodes or welding wire should never be touched with bare hands when in the holder or welding gun. Holders or welding guns should never be held under the armpits. Remember, hot work increases risk due to the reduced skin resistance when sweating occurs.

egulations (Standards - 29 CFR) - Table of Contents

• Part Number: 1910
• Part Title: Occupational Safety and Health Standards
• Subpart: Q
• Subpart: Welding, Cutting, and Brazing
• Standard No: 1910.254
• Title: Arc welding and cutting.

1910.254(a)

General -

1910.254(a)(1)

Equipment selection Welding equipment shall be chosen for safe application to the work to be done as specified in paragraph (b) of this section.

1910.254(a)(2)

Installation Welding equipment shall be installed safely as specified by paragraph (c) of this section

* The arc - the temperature can reach 6000 degrees celsius. The intense ultraviolet and infra-red rays can be harmful to both the welder and anyone else nearby.

* The electrical circuit - the electrical circuit is perhaps the greatest hazard to the welder. The risk of electrical shock is high and welders should note the following points:

o Never attempt to change welding cables before switching off the power.
o Always install the welding machine as near as possible to the power point.
o Always keep the welding machine terminals and cable connections clean.
o Work on a well insulated floor wherever possible.
o Always wear dry gloves when Handling equipment that is live.
o Always get a qualified electrician to do any electrical repairs.

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