TIG
Gas Tungsten Arc Welding, commonly referred to as "TIG" welding, is a high quality, commonly used welding process to produce precision welds. Temperatures of a TIG welder can reach up to 11,000°F. The benefits of TIG welding include: high quality welds, low distortion, precision control, free of spatter, and welds can be made with or without filler metal. Some TIG problems include: difficult arc starting, an erratic arc, porosity, excessive electrode consumption, arc wandering, and oxidized weld deposit.
MIG
Gas Metal Arc Welding, or "MIG" welding, is a high deposition rate welding process. Wire is fed through a spool during the welding procedure. Therefore, MIG welding is also commonly referred to as a semiautomatic welding process. Temperatures of a MIG welder can reach up to 10,000°F. MIG welding benefits include: all position capabiluty, less operator skill required, higher deposition rates, long welds can be made without starts and stops, and minimal post-weld cleaning is required. Some MIG welding problems include: irregular wire feed, porosity, burnback, unstable arc, heavily oxidized weld deposits, and difficult arc starting.
Flux Cored Welding
Flux Cored Arc Welding, or "FCAW," is a process similar MIG welding, but adds the benefit of flux, a chemical clean agent that removes oxidation from the metals being joined. It is a semiautomatic welding process similar to MIG welding, but produces a smoother weld appearance. Some benefits of Flux Cored Welding include: all position capability, high deposition rates, low operator skill required, good quality welds, and metallurgical benefits from a flux. Some problems include: melted contact tip, burnback, porosity, and irregular wire feed.
Stick Welding
Shielded Metal Arc Welding, or stick/covered electrode welding, is one of the most widely used welding process. The process uses a flux-covered electrode (an electrical conductor). The flux melts during the welding process, forming gas and slag that shields the arc and molten weld pool. After welding, the slag must be chipped off the weld bead. Temperatures of Stick welding can reach up to 6,500°F. Benefits of Stick Welding include: simple, inexpensive, and portable equipment used, lower sensitivity to wind and drafts, self-providing and regulating flux, and all position capability. Problems include: arc blow, rough surface, excessive spatter, porosity, poor arc stability, and incorrect weld profile.
Submerged Arc Welding
Submerged Arc Welding, or SAW welding, is a high quality, high deposition rate welding process. SAW welding is commonly used to join multiple plates of metal together. Some benefits include: extremely high deposition rates, easily automated, high quality welds, and low operator skill required. Some problems include: solidification cracking, incomplete fusion, porosity, hydrogen cracking, and irregular wire feed.
Resistance Welding
Resistance Spot Welding, Resistance Seam Welding, and Projection Welding are commonly used welding processes that uses the application of an electrical current and mechanical pressure to create a weld between two pieces of metal. Benefits of Resistance Welding include: high speed welding, suitable for high-rate production, easily automated, and economical. Problems include: cracks, pinholes, weld size, porosity/cavities, irregular-shaped welds, improper weld penetration, electrode deposite on work, surface appearance, and deep electrode indentation.
Electron Beam Welding
Electron Beam Welding is a fusion joining process that produces a weld by impinging, or colliding a beam of high-energy electrons to heat the weld joint. The electron beam is always generated in a high vacuum. A vacuum will provide maximum purity and high depth-to-width ratio welds. Benefits of Electron Beam Welding include: low distortion, single pass welding of thick joints, narrow weld zone, low contamination in a vacuum, heat-affected zone is narrow, no filler metal is used, complete seals of components retaining a vacuum, and dissimilar welds of some metals. Problems include: undercutting, cracking, lack of fusion, missed joints, porosity, underfill, and shrinkage voids.
Robotic Welding
There are two popular types of industrial welding robots: articulating and rectilinear robots. Rectilinear robots operate in an X, Y, Z axis. This creates a work zone that is box-shaped. Articulation robots employ the usage of arms and rotating joints, which allow the robot to move like a human arm, creating an irregularly-shaped working zone. There are many factors to consider when using a robotic welding system. These include: Accuracy and repeatablility, number of axes, reliability, fixtures, programming, seam tracking systems, maintenence, controls, weld monitors, arc welding equipment, positioners, and part transfer.
