احمد السيد مسعود خالد محمد عبد الواحد ابراهيم مجدي ابراهيم السيد SEC 1 SEC2 SEC1 wo rk sh op Definition: Welding is a fabrication process whereby two or more parts are fused together by means of heat, pressure or both forming a join as the parts cool. The parts that are joined are known as a parent material. The material added to help form the join is called filler or consumable. The form of these materials may see them referred to as parent plate or pipe, filler wire, consumable electrode (for arc welding), etc. Consumables are usually chosen to be similar in composition to the parent material, thus forming a homogenous weld, but there are occasions, such as when welding brittle cast irons, when a filler with a very different composition and, therefore, properties is used. These welds are called heterogeneous. The completed welded joint may be referred to as a weldment. Types of Welding Joints Welds Based on Configuration 1- Slot weld Joint between two overlapping components made by depositing a fillet weld around the periphery of a hole in one component so as to join it to the surface of the other component exposed through the hole. 2- Plug weld Weld made by filling a hole in one component of a workpiece with filler metal so as to join it to the surface of an overlapping component exposed through the hole (the hole can be circular or oval). Weld Based on Penetration 1- Full penetration weld Welded joint where the weld metal fully penetrates the joint with complete root fusion. In US the preferred term is complete joint penetration weld. 2- Partial penetration weld Weld in which the fusion penetration is intentionally less than full penetration. In the US the preferred term is partial joint penetration weld (PJP). Welds Based on Accessibility Features of Completed Welds Fillet weld Parent Metal Metal to be joined or surfaced by welding, braze welding or brazing. Filler Metal Metal added during welding, braze welding, brazing or surfacing. Weld Metal All metal melted during the making of a weld and retained in the weld. Welding technique sand convinent materials use d Different processes are determined by the energy source used, with a variety of different techniques available. Until the end of the 19th century, forge welding was the only method used, but later processes, such as arc welding, As shown i the fig: I thas two cable sone wil lbe Attache dt othe des ko rthe Metal table and the other Will hol dthe electrode, known as the shielded-metal arc welder, most people prefer it due to how easy it is to buy and the lack of a special environment needed to use it. But the electrodes in a stick welder require frequent replacement compared with other forms of welding. These include the gas tungsten arc machines, TIG and gas metal arc welder, known as MIG welders. You will also need some sort of gas feed with this type of welder. Charged Electrode An electrode is the tip of the tool that passes the current from the welder to the material being welded, making it so hot it becomes liquid. In the cases of the stick and MIG welders, the type of metal and the heat to melt it drives the type of electrode tip needed. But in a TIG welder, the electrode tip is made of non-consumable tungsten, and does not require replacement. Wire and Electrode Feeds Some welds require a feed to strengthen the joint due to the geometry or weakness of the weld. Stick welding uses the electrode to feed; MIG welding often uses a wire feed. And TIG welding likewise uses a feed due to its non-consumable nature. Most suitable welding techniques: SMAW, DC-TIG, MIG, FCAW, resistance Iron-based metals such as steel and stainless steel tend to work with the highest number of techniques compared to others. Low carbon mild steel acts as one of the most weldable metals available. Its composition includes low amounts of elements that can decrease the risk of a failed weld. Stainless steel has a more complex chemical composition, but it can also work with multiple techniques that account for oxidation. ALUMINUM Most suitable welding techniques: SMAW, AC-TIG, MIG Grades of aluminum that fall in the 1XXX and 6XXX series can undergo select welding techniques. A 1XXX series aluminum does not require much extra effort during the welding process, making it simple to handle. Meanwhile, a welder can work with 6XXX aluminum if they use proper welding operations and filler material. TITANIUM Most suitable welding technique: DC-TIG When a welder protects titanium from oxidation, they can use it to achieve sturdy and long-lasting results. Titanium requires full coverage from a shielding gas to provide a high level of weld integrity. CAST IRON Most suitable welding technique: SMAW Cast iron poses more difficulty during the welding process than metals such as steel or aluminum. Its high carbon content requires careful preheating and heating methods that provide gradual temperature changes. COPPER AND BRASS Most suitable welding technique: DC-TIG Copper and brass have high corrosion resistance that makes them useful for a variety of welding applications. During the welding process, the welder needs to account for any alloys in the material that cause cracks or oxidation. MAGNESIUM ALLOY Most suitable welding technique: AC-TIG A magnesium alloy has similar properties to aluminum. The magnesium in the alloy has a much lower melting point than oxides, making it critical to remove oxides before welding. oxy-acetylene The oxy-acetylene (and other oxy-fuel gas mixtures) welding torch remains a mainstay heat source for manual brazing and braze welding, as well as metal forming, preparation, and localized heat treating ComponentsT,w opipes hol dacetylene and oxyge ,ngas pipes ,control valve ,smixin gchamber ,nozzl.e An dals ow ecan notic eits power b ythe color o fthe flame depen do n the temperature. neutral since in most cases will have no A neutral flame is named .chemical effect on the metal being welded A carburizing flame will produce iron carbide, causing a chemical change in steel and iron. For this reason a carburizing flame is not used on metals that absorb carbon. An oxidizing flame is hotter than a neutral flame and is often used on .copper and zinc Welding Torch Flame Types. Shown: Carburizing flame (left), Neutral flame (center), Oxidizing flame (right) Temperature Gradient of a Neutral Welding Flame WELDING SERVICES FROM FAIRLAWN TOOL, INC. The welding process requires professional techniques and knowledge of weldable metals. Fairlawn Tool, Inc. provides robotic and manual welding services as part of our single-source metal fabrication solutions. Casing welding tha tw euse t oprotect oil and gas wells, BO Pwelding ,t ofix some column sand i nfixin gthe rig. Safety Equipment Due to the temperature and elements involved, welding is highly dangerous and can be lethal if handled incorrectly. Before you touch a welding setup, wear a welding helmet that protects your eyes, ear plugs, solid boots to protect your feet from sparks or slag, welding gloves to protect your hands and leathers to cover the rest of your body. Do not weld without these, as you will likely get hurt.
