To understand forehand and backhand welding you must for understand the basics of your work angle. Overhead mig welding requires the mig gun tilted 5 to 35 degrees toward the direction of the weld. The welder holds the welding torch in the right hand and the filler rod in the left. Mig welding vertical up technique require the nozzle point upward 35 to 45 degrees. The filler material is used to fill the gap between the parts to be welded. This method is used for welding steel plates under 6. Figure 16 rightward or backward technique 20 figure 17 blowpipe and rod angles for allposition rightward technique 21 figure 18 leftward technique 21 figure 19 multilayer technique. The sifbronze technique for successful sifbronzing or bronze welding, parts must be thoroughly cleaned and degreased and to obtain optimum strength a 60 90 vee preparation is required. Leftward technique the welder holds welding torch in his right hand and. When welding from left to right, maintain a 0 to 15degree angle tilted towards the direction of travel. Welding is started at the righthand end of the joint and proceeds towards the left. The torch is held at approximately a 45 degree angle from the vertical. Electrode welding stick welding is a manual arc welding process where an electric arc ignites between the used electrode and the metal as soon as they touch. Each is described in detail below including descriptions and illustrations of the forehand leave the weld behind you and move right to left for.
Due to less consumption of filler metal, the rightward technique involves lower cost of welding than leftward technique. By the end of this unit each apprentice will be able to. Chapter 3 introduction to welding in the navy as well as private industry, welding is widely used by metalworkers in the fabrication, maintenance, and repair of parts and structures. Tig welding how to tig weld, process overview and machine setup. When arc welding in a confined area, such as a boiler, tank, or the hold of a ship, bear in mind that all the hazards associated with normal arc welding are amplified, so the precautions mentioned here are even more important. The relationship between material thickness, blowpipe nozzle size and welding speed, is shown in the chart. With the aid of sketch, describe rightward and leftward gas welding methods. For welding vertical up, use a push or forehand technique and tilt the top of the electrode 0 to 15 degrees away from the direction of travel. I lucked up and got a gravy job the other day so i took the chance to shoot video on welding techniques using both mig and stick. Camtech has prepared this handbook on welding techniques to. Unit 1 oxyacetylene welding introduction duration 7 hours learning outcome. The electrode melts and creates the weld on the workpiece.
On other hand, the blowpipe is held much flatter i. Oxyacetylene gas welding technique edu support scribd. Leftward welding technique this is a welding technique in which the flame directed towards the unwelded part and the filler rod, when used is directed towards the welded part of the joint. I have gas welded for years, but never quite understood, the right ward or leftward technique, although i have probably done both without knowing it, ive had a read on this, but still dont get it, can anyone explain simply what the difference is. This paper studies the distortion mechanisms and the effect of welding sequence on panel distortion. Welding techniques leftward welding leftward welding is used on steel for flanged edge welds, for unbevelled plates up to 5. This will melt the interface part and join them permanently. Several mitigation methods, including preheating and prestressing the plates during assembly, have been investigated and used by some fabricators. In this method, the welding rod precedes the torch.
Apr 05, 2018 rightward welding technique anuniverse 22 s. Oxyfuel oxyacetylene welding a guide to gas welding twi. When it comes to mig welding techniques there are always two choices for the type of travel. It is also the method usually adopted for cast iron and nonferrous metals. The first lesson of welding learn to run a straight bead everlast powertig 200dv duration. Experience gained from user contact and welding training of crewmembers showed that. In horizontal welding, plates to be welded are placed in vertical plane while weld bead is deposited horizontally fig. The allpositional rightward method is a modification of the rightward technique and is ideally suited for welding steel plate and. In this welding process, mostly oxyacetylene gas is used as a working fuel gas.
Welding sparks can cause fires and explosions sparks and spatter from the welding arc can spray up to 35 feet from your work flammable materials should be removed from the welding area or shielded from sparks and spatter have a fire extinguisher ready inspect area for fires 30 minutes after welding. Covered electrodes for manual arc welding of non alloy and fine grain steel. The purpose of the welding handbook for maritime welders is to provide guidance in modern welding and related processes and to provide the welder with a source of practical information on the right solution to specific onboard welding problems. Typical shielded metal arc electrode positioning and welding technique for carbon steel electrodes table detailing differences in welding methods and techniques based on joint type and welding position forehand welding. Pipe horizontal 22 figure 20 blockwelding technique 22 table 1 sizing and alignment 3. In this technique, the torch is held in the right hand and the filler rod is. You want the heat to be on the hot side and once you do it.
Rightward welding technique this is a welding technique in which the flame is directed towards the welded part, and the filler red. Tungsten is a very hard, slightly radioactive, and brittle metal. The direction of welding is opposite to that when employing the leftward technique. In this technique, the torch is held in the right hand and the filler rod is in the left hand of the operator. Sep 16, 2017 the first lesson of welding learn to run a straight bead everlast powertig 200dv duration.
Source extraction local exhaust is a mechanical device used to capture welding fume at or near the arc and filter contaminants out of the air. Now the welding torch moved along the line where joint to be created. May 06, 2016 welding techniques depending upon the ways in which welding rod and the welding torch may be used, there are two usual techniques in gas welding, namely. Overheating must be avoided, as this will lead to porosity and inferior work.
The high temperature required for welding is obtained by the application of a flame from mixture of oxygen and acetylene gas. Mig welding techniques, paterns and angles for all position. Equipment, flames, working, advantage, applications. Camtech has prepared this handbook on welding techniques to provide. It is essential to ensure that your welding and cutting equipment is protected, as far as possible, against. Introduction welding is a process for joining different materials. Welding begins at thew left hand end of the joint and proceeds towards the right, hence the name rightward technique. The leftward technique is used almost exclusively and is ideally suited for. Oxyfuel oxyacetylene welding a guide to gas welding. Top 4 techniques of gas welding metallurgy your article library. This technique is comparatively more difficult than flat welding. With a neat sketch, describe turning between centres. This method is used for welding plates upto 5 mm thick.
The welding process is a material joining process which process, which produces. An introduction to welding how to oxyacetylene weld. The rightward technique finds an application on plate thickness above 5 mm for welding in the flat and horizontalvertical position. The work angle is basically the angle of your electrode or welding torch in relationship to the surface of the metal the base metal as its referred to you are welding. Stick welding shielded metal arc welding smaw, also known as manual metal arc mma welding or informally as stick welding, is a manual arc welding process that uses a consumable electrode coated in flux to lay the weld. You want the heat to be on the hot side and once you do it for a while it is as easy as flat. The torch is bulky and hence manual welding is a bit difficult and requires training. An electric current, in the form of either alternating current or. You can only weld bare metal remove oxides, paints, oils, rust, etc prepare jointsinterfaces make every part fit the best you can before welds for wheelchair tubing, may need to assemble jigs clamp carefully be patient and calm. In tig welding the tungsten is made into a non consumable electrode that is used to create the arc for tig welding. The principal techniques employed in oxyacetylene welding are leftward, rightward and allpositional rightward.
The leftward method of welding is also known as forward welding. Oxyacetylene gas welding technique knowledge zone, the. Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. Leftward welding technique this is a welding technique in which the flame directed towards the unwelded part and the filler rod, when used is directed towards the welded part of the joint rightward welding technique this is a welding technique in which the flame is directed towards the welded part, and the filler red. The allposition rightward technique is a modification of the above and is particularly suitable for mild steel plate and pipe in. Leftward welding technique is usually used for welding relatively thin metals. The program aims to facilitate employment and entry into the apprenticeship program by giving you practical experience with trade regulations and practices. Here you will learn what the differences are and when to use them. Identify and safely assemble regulators, hoses, torch and cylinders identify and understand the function of the component parts of the welding torch. Using leftward welding technique, the parts should. Leftward welding is used on steel for flanged edge welds, for unbevelled.
The leftward technique is used almost exclusively and is ideally suited for welding butt, fillet, and lap joints in sheet thickness up to approximately 5 mm. This is often done by melting the workpieces and adding a filler material to form a pool of molten material the weld pool that cools to become a strong. Typical other uses for tungsten are in light bulbs, heating elements, and rocket engines. Shielded metal arc welding is the process of joining two metal pieces using a flux covered electrode which is melted in an electric arc and becomes a fused part of the pieces being welded. Leftward welding technique this is a welding technique in which the flame directed towards the unwelded part and the filler rod. In terms of the absolute number of welds made, fusion welding is the most common welding technique.
The reason being that thicknesses up to 8 mm need not be beveled, whereas for butt joints in plate over 8 mm, the included angle of the v preparation is only 60. Oxyacetylene gas welding technique there are different welding techniques for welding mild steel. Welding is a very common metal joining technology and it is widely used in railways in various production and maintenance units. Humbers welding techniques certificate program is designed to help introduce prospective welders to the trade. Mike tarkanian dmse technical instructor 8014 march 16.
Railways recruit iti qualified welders as well as promote staff to welder category by providing appropriate training. This article throws light upon the top two techniques of welding. No edge preparation is required in case of the plates of thickness upto 3 mm. The hose check valve has reduced the incidence of backfeeding in which oxygen contaminates fuel gas hose or vice versa.
This subject is very complicated and only these precautions related to arc welding will be discussed in this brochure. The fusion welding processes are classified in terms of the source of heat used to cause localized melting. Weldingdefinition, type detail, advantage disadvantage. The weld quality is better than that obtained from leftward technique. Welding techniques depending upon the ways in which welding rod and the welding torch may be used, there are two usual techniques in gas welding, namely. Modern electrodes are typically made of a core rod and are flux coated. Liquid petroleum cylinders are painted aluminium and have lefthand. Welding 2 round stock into 1 thick a36 hot rolled steel. In this method, welding is started from right hand side of the joint and proceeds towards left. See image below for what the work angle looks like on a groove and fillet weld.
Five steps to improving your stick welding technique. The welding technique used may be leftward welding or rightward welding. Welding parameters for horizontal welding should be selected carefully for easy manipulationplacement of weld metal at the desired location. At the end of the articles you will find the download pdf button that you can. Oxygenacetylene welding, or gas welding, is a process which relies on.
Nov 20, 2016 the welding technique used may be leftward welding or rightward welding. Mig welding techniques, paterns and angles for all. Mike tarkanian dmse technical instructor 8014 march 16, 2007. This article throws light upon the top four techniques of gas welding. Each of the above type of welding can be further classified depending on other micro level characteristics. Camtech has prepared this handbook on welding techniques to provide basic information on the subject. Ahw atomic hydrogen welding caw constricted arc welding tig tungsten inertgas arc welding mig metal inertgas arc welding mag metal activegas arc welding pjw plasma jet welding paw plasma arc welding pjpw plasma jet plasma arc welding gmgmma gasmixture shielded metalarc welding magm magc co2shielded metalarc welding ngw narrowgap welding. When carrying out fusion welding the addition of filler metal in the form of a rod can be made when required.
In order to join two or more pieces of metal together by welding process the most. Welding thinplate panel structures often results in warping of the panels. Dec 12, 2019 typical shielded metal arc electrode positioning and welding technique for carbon steel electrodes table detailing differences in welding methods and techniques based on joint type and welding position forehand welding. The smaller volume for deposited metal as compared to leftward welding reduces shrinkage and distortion. The blowpipe is given a forward motion with a slight sideways movement to maintain melting of the edges of both plates at the desired rate and the welding rod is moved progressively along the weld seam see fig. Aug 14, 2009 for welding vertical up, use a push or forehand technique and tilt the top of the electrode 0 to 15 degrees away from the direction of travel. The leftward welding technique is used and the parts should be heated with an.
1306 1468 828 813 451 577 1376 512 1533 620 953 230 1097 1303 1079 343 510 1171 502 929 1532 292 1015 58 754 585 58 1406 647 178 889 1431 1148