Showing posts with label hardfacing. Show all posts
Showing posts with label hardfacing. Show all posts

Tuesday 3 January 2012

BASIC WELDING TERMS

What is Arc Welding?
Arc welding is a method of joining two pieces of metal into one solid piece. To do this, the heat of an electric arc is concentrated on the edges of two pieces of metal to be joined. The metal melts, while the edges are still molten, additional melted metal is added. This molten mass then cools and solidifies into one solid piece.

Welding Consumables

Stick Electrode A short stick of welding filler metal consisting of a core of bare electrode covered by chemical or metallic materials that provide shielding of the welding arc against the surrounding air. It also completes the electrical circuit, thereby creating the arc. (Also known as SMAW, or Stick Metal Arc Welding.) Basic Welding Terms
MIG Wire
 Like a stick electrode, MIG wire completes the electrical circuit creating the arc, but it is continually fed through a welding gun from a spool or drum. MIG wire is a solid, non-coated wire and receives shielding from a mixture of gases. (Process is also known as GMAW, or Gas Metal Arc Welding.)
Basic Welding Terms
Cored Wire (Flux-Cored Wire)
 Cored wire is similar to MIG wire in that it is spooled filler metal for continuous welding. However, Cored wire is not solid, but contains flux internally (chemical & metallic materials) that provides shielding. Gas is often not required for shielding. (Process is also known as FCAW, or Flux-Cored Arc Welding.)
Basic Welding Terms
Submerged Arc 
A bare metal wire is used in conjunction with a separate flux. Flux is a granular composition of chemical and metallic materials that shields the arc. The actual point of metal fusion, and the arc, is submerged within the flux. (Process is also known as SAW, or Submerged Arc Welding.)
Basic Welding Terms 
Stainless Steel
Stainless steel electrodes and wire are used for welding applications where corrosion resistance is required. Stainless steel consumables are designed to match the composition of stainless steel base metals.
Basic Welding Terms 

Hardfacing
A stick of electrode or cored wire that is designed not to fuse two pieces of metal together, but to add a layer of surface metal to a work-piece in order to reduce wear. An example of this is the shovel on an excavator.
Basic Welding Terms 
Welding Equipment

Stick Welders Heating the coated stick electrode and the base metal with an arc creates fusion of metals. An AC and/or DC electrical current is produced by this machine to create the heat needed. An electrode holder handles stick electrodes and a ground clamp completes the circuit. Basic Welding Terms
TIG Welders 
A less intense current produces a finer, more aesthetically pleasing weld appearance. A tungsten electrode (non-consumable) is used to carry the arc to the workpiece. Filler metals are sometimes supplied with a separate electrode. Gas is used for shielding. (Process is also known as GTAW, or Gas Tungsten Arc Welding.)
Basic Welding Terms
MIG Welders and Multi-Process Welders
Constant Voltage and Constant Current welders are used for MIG welding and are a semi-automated process when used in conjunction with a wire feeder. Wire is fed through a gun to the weld-joint as long as the trigger is depressed. This process is easier to operate than stick welding and provides higher productivity levels. CC/CV welders operate similarily to CC (MIG) welders except that they possess multi-process capabilities - meaning that they are capable of performing flux-cored, stick and even TIG processes as well as MIG.
Basic Welding Terms
Engine Driven Welders
Large stick or multi-process welders are able to operate independent of input power and are powered by a gasoline, diesel, or LPG engine instead. Ideal for construction sites and places where power is unavailable.
Basic Welding Terms
Wire Feeder / Welders
For MIG welding or Flux-Cored wire welding, wire feeder welders are usually complete and portable welding kits. A small built in wire feeder guides wire through the gun to the piece.
Basic Welding Terms
Semiautomatic Wire Feeders
For MIG welding or Flux-Cored welding, semiautomatic wire feeders are connected to a welding power source and are used to feed a spool of wire through the welding gun. Wire is only fed when the trigger is depressed. These units are portable.
Basic Welding Terms
Automatic Wire Feeders
For MIG, Flux-Cored, or submerged arc welding, automatic wire feeders feed a spool of wire at a constant rate to the weld joint. They are usually mounted onto a fixture in a factory/industrial setting and are used in conjunction with a separate power source.
Basic Welding Terms
Magnum Guns / Torches
MIG welding guns and TIG welding torches are hand-held welding application tools connected to both the wire feeder and power source. They direct the welding wire to the weld joint and control the wire feed with the use of a trigger mechanism.
Basic Welding Terms



Cutting

Plasma Cutters
A constricted cutting arc is created by this machine, which easily slices through metals. A high velocity jet of ionized gas removes molten material from the application.
Basic Welding Terms 
Oxyfuel Gas Cutting
Oxyfuel gas cutting process involves preheating the base metal to a bright cherry red, then introducing a stream of cutting oxygen which will ignite and burn the metal.
Basic Welding Terms 

Welding Automation / Robotic Welding
Robotic Welding Systems
The combination of a robotic arm, a welding power source and a wire feeder produces welds automatically using various programs, welding fixtures and accessories.
Basic Welding Terms 
Environmental Systems
Also known as fume extraction, these systems are often incorporated into a robotic fixture to remove welding fumes natural to the process from the welding environment. Usually a vacuum unit, they can be portable or mounted onto a wall.
Basic Welding Terms