Ten years ago, the AWS Forum hosted a discussion around green welding. Since that discussion, greener welding techniques and practices have become more familiar.

This article looks at the ways the welding process can affect the environment and discusses ideas for increasing environmental friendliness and long-term sustainability.

Environmental impacts of welding

The welding process directly generates two broad categories of detrimental byproducts: toxic emissions and process heat. These byproducts most often affect the welder’s immediate environment rather than the community surrounding a welding shop or plant. Emissions include minute particles, including nano-sized particles, of metal oxides and gases like carbon monoxide, ozone and various nitrogen oxides.

These immediate and direct negative byproducts are not the only components of the welding process that generate environmental damage and negatively impact sustainability. Process inputs like electrical energy, filler material, consumable electrodes and shielding gas have direct costs for the company and less-obvious environmental costs. Generating electricity most often requires consumption of natural resources that must be mined. The slag and electrode stubs must be properly disposed of to prevent them from further polluting the environment.

Greener ways to weld

One article on sustainable welding practices suggested, among more prosaic ideas, using old welding helmets as planters. The following less fanciful recommendations can reduce the environmental impact and contribute to sustainability.

Different welding techniques generate different amounts and kinds of pollutants, so selection of technique has an impact on environmental impact. Two solid-state welding techniques, friction stir welding (FSW) and magnetic pulse welding (MPW) create less pollution because they eliminate the need for fillers or flux and do not produce dangerous fumes. Another solid-state technique, diffusion welding, also eliminates outgassing, but it is impractical for large jobs.

Figure 1: Modern welding processes are typically greener than many older methods. Source: NIST

Among other techniques, researchers in Germany compared manual metal arc welding (MMAW or SMAW), laser arc hybrid welding (LAHW) and gas metal arc welding (GMAW) across several environmental factors and concluded that LAHW created the lowest direct environmental impact, with GMAW a close second. The lack of flux and electrode stubs and lower electricity use accounted for much of the difference.

What if the best process for a job is not one of these? One writer suggested looking at the welding process chain and evaluating whether and how to reduce the environmental and cost impacts of each of these links in the chain:

· Welding speed

· System costs

· Raw materials

· Processing time

· Filler metals

· Seam quality

Other smart practices

Beyond optimizing welding techniques, companies can adopt other practices to protect the environment and their bottom lines. Recycling scrap materials is an obvious suggestion; eliminating as much scrap as possible by reducing production waste is another.

Lincoln Electric proposed an unexpected suggestion: greening the welding process starting by training welders using virtual reality. By providing virtual tools and materials, VR reduces training costs and eliminates the environmental impact of actual welding. And initial training is the right time to introduce new welders to new ways to start their careers knowing how to ply their trade in an environmentally responsible and sustainable way.