Gas welding is accomplished by melting the edges or surfaces to be joined by gas flame and allowing the molten metal to flow together, thus forming a solid continuous joint upon cooling. The flame plays lead role to create weld joint and the weld properties are highly depended on it. The primary gas combination for gas welding is an oxygenacetylene mixture, but other gases are used. Arc welding is the most common type of welding process used in construction. Wear flame resistant clothing when gas welding or cutting. As per the requirement the type of flame can be generated. Oxidizing welding flames are commonly used to weld these metals. Fundamentals of gas cutting and welding cedengineering. Safety in gas welding, cutting and similar processes hse. In my last post, we have discussed about gas welding. Arc welding uses intense heat to melt metal, causing the molten. The correct type of flame is essential for satisfactory welding.
A stronger oxidizing flame is used in the welding of brass or bronze. Safety instructions for parweld gas welding and cutting. Chapter 41 welding and cutting 41 welding and cutting welding is a method of joining metal parts together by heating them until they melt and pressing them together. They include standards for quality in arc welding, aerospace, stud welding and other. The neutral or balanced flame is obtained when the mixed torch gas consists of approximately one volume of oxygen. In most cases, the amount of excess oxygen used in this flame must be determined by observing the action of the flame on the molten metal. Raw acetylene gas has a very strong odour worse than propane. The neutral flame has a clear, welldefined or luminous cone. Gasshielded arc welding of aluminium gasshielded welding can be divided into the tungsten gasshielded welding and the. The carburizing flame, in which an excess of acetylene is burned, is used when welding nickel alloys. Most textbooks do not cover smaller diameter electrodes well. Arc welding power sources transformer, motor generator set, rectifier and inverter type welding machines. This flame directly strikes the weld area and melts the weld surface and filler material. Oxyacetylene welding oaw, is the most commonly used gas welding process because of its high flame te.
It is done by burning of fuel gases with the help of oxygen which forms a concentrated flame of high temperature. The flame from an oxyfuel gas torch often called a blowpipe is a very powerful. The flux melts, solidify and forms a slag on the resultant weld bead. Rules for classification and construction vi additional. Welding welding is a materials joining process which produces coalescence of materials by heating them to suitable temperatures with or without the application of pressure or by the application of pressure alone, and with or without the use of filler material. British standards for welding general welding key standards these general standards are an important supplement to the more speci. The fuel gas commonly acetylene, when mixed with proper proportion of oxygen in a mixing chamber of welding torch, produces a very hot flame of about 57005800f. Gas welding this chapter discusses equipment and materials used in gas welding.
At the end of the articles you will find the download pdf button that you can easily download pdf. When brazing, the filler material is drawn into a closefitting joint by capillary attraction. It is a welding process that melts and joins the metals by heating them with a flame caused by a reaction of fuel gas and oxygen. Gas welding is a most important type of welding process. With over 50 years combined experience, the authors have created a book that is both referencefriendly and incredibly. In the hot gas speed welding technique, the rod is fed into the joint via a tube in the speedwelding nozzle see fig.
The oxidizing flame, in which an excess of oxygen is burned, is used for welding bronze or fusing brass and bronze. Design, equipment and testing of gas welding installations on seagoing ships a. They must be placed at least 20 feet from combustibles, sparks, excessive heat and open flames. The melted part of welding plates diffused in one another and create a weld joint. This article throws light upon the three important types of gas flames essential for welding of metals. There are three basic types of oxyacetylene flames viz. The most important welding variables are the arc energy per unit length of the weld and the welding speed. Types of welding flames members gallery mechanical. Types of welding position this chapter presents common types of welding position and various difficulties associated with them. Fundamentals of gas cutting and welding ced engineering. Safety and health at work for gas welding and flame cutting. Oxyfuel welding, commonly referred to as oxy welding or gas welding is a process of joining metals. Before going to gas welding let me discuss what is welding so, welding is defined as a fabrication process that joins materials, usually metals or.
Special tips are available to perform other tasks such as heating. Braze welding brazewelding can be used to join similar or dissimilar metals by using a filler material with a lower melting temperature range than the parent metals being joined. Oxyacetylene gas welding is commonly used to permanently join mild steel. Find materials for this course in the pages linked along the left. Seminar on gas welding seminar report pdf download.
Flat welding, horizontal welding, vertical and overhead welding, groove weld, edge. The selection of flame depends on the type of material to be weld and the required properties after welding. The most commonly used method is oxyacetylene welding, due to its high flame temperature. This process is particularly suitable for joining metal sheets and plates having a thickness of 20 to 50 mm. This is the neutral mapp gas flame for welding, shown in figure 1.
Welding goggles or face shields, filter out ultraviolet and infrared rays and protect the operators eyes. Simulation of tack welding procedures in butt joint. Oxyfuel gas welding ofw is a manual process in which the metal surfaces to be joined are melted progressively by heat from a gas flame, with or wit. The correct composition of gas mixture and gas welding flames is important for gas welding process. Further, need for edge preparation and the rationale for selection of suitable groove design have also been presented. In this welding process gases fuels are burn and produce high temperature flames which further used to create weld joint.
Unfortunately, gas welding isnt taught as regularly as it. This welding on the web box will appear throughout the manual. Lecture notes welding and joining processes materials. A mixture of oxygen and acetylene, burns as an intense focussed flame, at approximately 3,500 degrees centigrade. The process uses shielding from an externally supplied. Traditionally oxyfuel processes are used for brazing, fusion welding, flame hardening, metalizing. The flame must be of the proper temperature, size and shape in order to take a highest efficiency.
The neutral flame has a clear, welldefined, or luminous cone indicating that combustion is c. Different types of flames are used depending on the particular welding application. The neutral flame, in which a balanced mixture of oxygen and acetylene is burned, is used for most welding operations. Applying fuel gas welding fgw processes and techniques. Gas welding and cutting oxyfuel welding, commonly referred to as oxy welding or gas welding is a process of joining metals by application of heat created by gas flame. A slot weld is similar to a plug weld except that the hole. The flux may be used to deoxidize and cleanse the weld metal. A plug weld is a weld made in a circular hole in one member of a joint fusing that member to another member. All contact points should be rounded, including holddown clamps, to permit aluminum to expand while materials are being welded. The speedwelding nozzle also introduces hot air to the filler rod and to the joint. When the feather disappears, the oxyfuel ratio is about 2. The welding installation consists of the welding power source, the shielding gas supply, the wire feed device, the control unit and the hose package with the welding torch. The welder can change the performance of the welding torch by adjusting the ratio of the gases, which in turn changes the properties of the flame. It is also desirable to tack weld whenever possible.
Today we will learn about types of welding flames used in gas welding. As oxygen is increased, or the fuel is turned down, the carburizing feather pulls off and disappears. Importance of putting dimension on the drawing as per bis. Gas welding is a welding process that melts and joins metals by heating them with a flame caused by the reaction between a fuel gas and oxygen. Use jigs designed to minimize heat loss using point contact. Gas welding is a process of construction that involves the use of gases as well as oxygen to weld metals together. Developed in 1903, gas welding is used to weld pipes and tubes together while also being an effective way to repair metal. Oxyfuel gas equipment has many uses welding, cutting, heating, straightening. The heat transfer properties of primary and secondary flames differ for different fuel gases. A welding tip is used for welding pieces together and a cutting attachment with a tip is used to cut metal. Neutral welding flame the neutral flame has a onetoone ratio of acetylene and oxygen.
Cylinders should not be stored near stairways, elevators or shafts. Never use matches or a cigarette lighter to ignite the oxyacetylene torch. Other names for gas welding are oxyacetylene welding and oxy welding. In this types of gas welding flames is provided the equal amount of oxygen and acetylene are mixed and to allow burn with above 3260. It obtains additional oxygen from the air and provides complete combustion. Pdf the effect of gas metal arc welding gmaw processes. When the flame comes in contact with steel, it melts the surface forming a molten pool, allowing welding to. The shielding gas, the welding current and, as the welding. Oxyfuel gas welding welding, brazing and soldering handbooks. Definition, equipment, flames, working, types, advantages, disadvantages, applications in detail note. Amount of gases to be mixed is controlled by the hoses levers situated on the welding torch from where the gases will pass.