Welding and fabrication techniques

Welding and fabrication techniques

Welding Basics

  • Welding is a process that uses heat, pressure, or both to join or fuse materials together, usually metals or thermoplastics.
  • The most common welding methods are Stick (SMAW), MIG/MAG (GMAW), TIG (GTAW) and Flux-cored (FCAW).
  • The primary purpose of welding is to create a strong bond between two or more pieces of metal that can withstand stress and strain.

Types of Welding Processes

MIG Welding

  • MIG (Metal Inert Gas) or GMAW (Gas Metal Arc Welding) uses a continuous solid wire electrode that is heated and fed into the weld pool from a welding gun.
  • The process involves a shielding gas that protects against contamination.
  • MIG welding is known for its speed and versatility.

TIG Welding

  • TIG (Tungsten Inert Gas) or GTAW (Gas Tungsten Arc Welding) uses a non-consumable tungsten electrode to produce the weld.
  • TIG welding is used when precision is essential, and it provides high-quality, spatter-free welds.

Stick Welding

  • Also known as SMAW (Shielded Metal Arc Welding), uses an electrode coated in flux that protects the weld area.
  • Stick welding is the most common type of welding, due to its versatility and simplicity.

Flux-Cored Welding

  • Flux-Cored Arc Welding (FCAW) is a process that uses a constantly fed electrode and a constant voltage or constant current power supply.
  • It’s primarily used for mild and low alloy steels.

Fabrication Techniques

Metal Forming

  • Includes techniques such as bending, stretching, and shaping metal into the required shape.
  • Involves applying force to the material to alter its geometry without removing any material.

Cutting

  • Metal cutting methods include plasma cutting, laser cutting, and water jet cutting.
  • Cutting transforms a metal sheet into a defined shape or size.

Assembly

  • The final step in the fabrication process involves assembling the cut and formed parts to create a finished product.
  • Methods of assembly can include welding, riveting, or using adhesives.

Tools and Equipment

Welding Machines

  • Depending on the welding technique, different machines and tools are used.
  • MIG and TIG welders, Stick welders, and Flux-Cored welders are the main types of welding machines.

Safety in Welding and Fabrication

  • There are several critical safety considerations in welding and fabrication.
  • Workers should use protective clothing like welding helmets, gloves, and safety glasses to protect against sparks, spatter, and intense light.
  • Adequate ventilation is also crucial as welding can produce harmful gases.

Waste and Recycling

  • Waste from welding and fabrication can include offcuts of metal and used-up welding rods or wire.
  • Proper waste management is essential in welding, and scrap metal from the process can often be recycled.