Oxy-fuel welding (OFW) is also known as Gas welding or Oxy-fuel gas welding. The term ‘Oxy-fuel’ is used to denote a combination of Oxygen and a Fuel gas, means it’s a process in which Oxygen and a fuel (combustible gas) both are required. Most commonly used fuel gas is Acetylene and thus the name Oxy-Acetylene welding (OAW) is also used for this process, when Acetylene is used as a fuel….
Heating the base metal to a specific desired temperature before welding is called as preheating. The temperature at which the base metal is heated is called as the preheat temperature. Preheat temperature can be determined by the applicable code. Please see table 1 to know how to find the preheat temperature in the respective code: In absence of code, the following factors shall be considered for determining the preheat temperature;….
Submerged Arc Welding (SAW) is an arc welding process in which arc is generated between a bare electrode and the workpiece. The arc and the molten weld pool are submerged in a blanket of granular fusible flux on the workpiece. Flux covers the arc and prevents fumes, sparks, spatter, and intense ultra violet radiation from escaping, which makes this process very different from other arc welding processes. Submerged arc welding….
Flux cored arc welding (FCAW) is a welding process that uses the heat produced by an arc generated between a continuous tubular filler metal (electrode) and the work piece. The filler metal is hollow with flux at the core. Flux present at the core of the filler metal shields the molten weld pool from atmospheric contamination. Flux Cored Arc Welding are mainly of two types: Self-Shielded (FCAW – S) Gas….
Gas Tungsten Arc Welding (GTAW) is also known as Tungsten Inert Gas Welding (TIG Welding). It is an arc welding process that uses a non-consumable electrode made up of Tungsten (or alloy of tungsten). Arc is generated between the tungsten electrode and work piece to establish the weld pool. Inert gas (Argon or Helium) is used to shield the molten weld pool during welding. Additional filler metal may be added….
A welding procedure specification (WPS) is a written document providing direction to the welder (or welding operator). It contains all the necessary parameters viz. joints, base metals, filler metals, positions, preheat, PWHT, gas etc. (including ranges, if any) under which the welding process must be performed. These parameters are known as variables (as per ASME Section IX). Three types of variables are mentioned in the code, these are; Essential Variable….
Welding symbols are a set of information conveyed by the design department to the welding Engineer and the welding operator. It contains all the necessary information viz. welding position, dimensions and geometry of the weld, details of groove/fillet, welding process etc. A basic weld symbol consists of three parts namely; Arrow Line Reference Line Tail These are shown in the diagram given below Arrow Line: Arrow indicates the position of….
The American Welding Society defines a joint as “the manner in which materials fit together.” there are five basic types of weld joints: • Butt joint. • T-joint. • Lap joint. • Corner joint. • Edge joint. 1. Butt joint: Butt joints are end to end joint, in which the parts lie in the same plane and are joined at the ends. 2. T-joint: In a T-joint (also called as….
In GTAW (Gas Tungsten Arc Welding) also known as TIG welding (Tungsten Inert Gas welding), a non consumable electrode (made up of Tungsten) is used. Tungsten is preferred due to high its high melting point (approximately 3,4100C) and high hardness. Either pure tungsten is used as electrode or it can be alloyed with other elements. These electrodes come in a variety of sizes and lengths. These electrodes are color coded….
Plate Welding Positions For plate welding we have four different positions namely; Flat position (1G or 1F) Horizontal Position (2G or 2F) Vertical Position (3G or 3F) Overhead Position (4G or 4F) Note: 1. G Designates groove welding (V-groove, J-groove, U-groove etc.) 2. F Designates fillet welds (“T” – Joint, Lap Joint etc.) FLAT WELDING POSITION (1G OR 1F) In flat welding the welders head….
GMAW (MIG welding) electrodes are designated by some letters and numbers such as ER70S-6, ER90S-6 and E308L etc. I will explain the meaning of these symbols: FOR CARBON STEEL OR MILD STEEL (SUCH AS ER70S-6 OR ER70S-3) Where, ER – Designates electrode or filler rod XX – Designates the minimum tensile strength of the deposited weld metal S – Stands for solid wire Y – Designates the chemical composition of….
Gas Metal Arc Welding (GMAW) is also known as Metal Inert Gas Welding (MIG welding). In this process, consumable electrode is used in the form of wire and a shielding gas such as Argon, Helium, Carbon dioxide or a mixture of these gases are used. These gases shield the molten weld pool from atmospheric contamination. The shielding gas is allowed to flow through the weld gun. Electrode of MIG welding….