Welding and Joining Processes

Flashcards related to the lecture notes on Welding and Joining Processes.

Joining Process

A manufacturing technique used to connect two or more separate materials, parts, or components to form a single functional unit by mechanical, thermal, or chemical means.

Fusion Welding

Melting together and coalescing materials by means of heat.

Filler Metals

Metals added to the weld area during welding.

Autogenous Welds

Fusion welds made without the use of filler metals.

Oxyfuel – Gas Welding (OFW)

A general term used to describe any welding process that uses a FUEL GAS COMBINED with OXYGEN to produce a FLAME.

Neutral Flame

Ratio of 1:1 acetylene and oxygen in the gas mixture.

Oxidizing Flame

Greater oxygen supply.

Carburizing Flame

Insufficient oxygen in the flame, the flame is a reducing flame

Pressure-gas Welding

Welding of two components starts with the heating of the interface by means of a torch using an oxyacetylene–gas mixture

Arc Welding

Heat required is obtained from electrical energy.

Straight Polarity

The workpiece is positive (anode), and the electrode is negative (cathode). It produces welds that are narrow and deep

Reverse Polarity

The workpiece is negative, and the electrode is positive. The weld zone is shallower and wider.

Gas Tungsten-Arc Welding (GTAW)

Also known as Tungsten Inert Gas – TIG Welding. Tungsten electrode doesn’t melt or become part of the weld and uses Argon or helium as an Inert Shielding Gas

Plasma-Arc Welding (PAW)

A concentrated plasma arc is produced (High Temperature Arc (~28,000°C)) and directed towards the weld area. A plasma is an ionized hot gas composed of nearly equal numbers of electrons and ions

Transferred Arc

Arc is between electrode and workpiece (used for welding).

Non-Transferred Arc

Arc is between electrode and nozzle (used for cutting or heating).

Atomic-Hydrogen Welding

An arc is generated between two tungsten electrodes. Hydrogen gas acts as a shielding gas and heat carrier

Shielded metal-arc welding (SMAW)

Electric arc is generated by tip of a coated electrode against the workpiece. The electrode serves as both the filler metal and the arc conductor.

Submerged-arc Welding (SAW)

The weld arc is shielded by a granular flux

Gas Metal-arc Welding (MIG)

The weld area is shielded by an effectively inert atmosphere of gases. The consumable bare wire is fed automatically through a nozzle into the weld arc by a wire-feed drive motor.

Flux-cored Arc Welding (FCAW)

Arc shield composed of vaporized and slag-forming compounds protects metal transfer through arc.

Electrogas Welding

Used for welding the edges of sections vertically and in one pass with the pieces placed edge to edge. The weld metal is deposited into a weld cavity between the two pieces to be joined

Electron-beam Welding (EBW)

Heat is generated by high velocity narrow-beam electrons.

Laser-beam Welding

Utilizes a high-power laser beam as the source of heat to produce a fusion weld