This category contains articles that address such as welding arcs, various welding positions, weld joint design, welding polarity, multipass welding, pipe welding processes, pipe welding positions, electric welding circuits, etc.
This article discusses a few aspects related to welding with alternating current, that is – AC welding. The article begins with an introduction to alternating current, followed by features of arc welding with alternating current. Features of Alternating Current Alternating current, as the name suggests, alternates between a positive value and negative value, according to … Read more
When an application requires a hard surface, it is not necessary that the entire body of the part be made up of a hard material. That would be uneconomical. A better way is to achieve hardening of the surface alone, while the base metal underneath continues to be plain carbon steel. This is called surface … Read more
Welding over paint is not a straightforward matter as it might seem. Paints are made of complex chemical substances that vaporize upon coming in intense heat of the welding or cutting arc. These chemical vapors can be harmful to the health of personnel. Hence, welding directly over paint is generally discouraged. Most codes and standards … Read more
In welding – besides the current current power source, the second type of power source is the constant voltage (CV) machine or the constant potential (CP) machine. It has a relatively flat volt-ampere characteristic curve. In this article we shall discuss about arc welding with constant voltage. Features Of A Constant Voltage Machine The figure below shows … Read more
The power source is the most important part of the arc welding equipment. In all arc welding processes, two kinds of power sources are generally used, from a voltage-ampere output characteristics point of view. One is constant current type, the second is constant voltage type. This article details the constant current type power sources in … Read more
This article discusses the auxiliary items (besides the power source) that enable a safe, quality welding. Besides the power source, other arc welding equipment includes welding cables, electrode holders, welding tables, clamps, backup bars, helmets, goggles, and accessories. This article briefly touches upon these. Cables Two welding cables are used in all arc welding machines. … Read more
The term arc welding is a very broad term that includes a wide variety of welding processes, that can all be grouped under this one term. As the name indicates, in arc welding – the heat of an electric arc is utilized to melt the base metal and obtain coalescence. The electric arc has a … Read more
This article describes a few aspects of forehand welding and backhand welding in oxyfuel welding process. Before we get into the specifies, let us understand a few related terms, such as work angle, push angle, travel angle, etc. Work Angle For a butt weld between two plates, imagine a plane cutting the base plates perpendicularly. … Read more
This article discusses in brief about expansion and shrinkage in welding, its effects, and remedies. Welding invariably involves heat. We know that metal expands when heated, and contracts when cooled. When molten metal is added to the joint, some of the sidewalls also get melted and get fused with the freshly deposited weld metal. This … Read more
Multilayer welding, as the name suggests, is the name given to welds which are made by using multiple layers of weld. Using multiple layers becomes necessary when welding of thick sections is being done. High thickness base metals cannot be welded with a single pass, as the resulting bead would be too big, unwieldy, and … Read more