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Advances in welding technology continue to create efficiencies for the businesses who adopt them. Applying best practices help ensure weld quality and efficiency.

Strengthening Metal Parts with Hardfacing

27 April, 18 2:42 pm · Leave a comment · reddarc
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Metallic parts sometimes fail their intended use at a lower stress than they are designated for.
Various forms of wear such as abrasion, impact, metal to metal contact, heat, and corrosion can compromise the strength of metal pieces. This is where hardfacing comes in. Hardfacing is a technique which can be applied to minimize the damage from these types of wear, helping to prolong the life of metal pieces.

What is hardfacing?

Hardfacing —often called hardsurfacing— is the covering of the metallic part with a wear resistant metal by welding. Alloys which commonly need to be hardfaced include carbon alloy and low alloy steels whose carbon content is lower than 1 %. These include stainless steels, manganese steels, cast iron as well as nickel and copper-based alloys.

Metallic parts sometimes fail their intended use at a lower stress than they are designated for.

Techniques, Materials and Costs

The particular hardfacing technique for a job depends on the geometry of the part and relative cost of the hardfacing method. Costs can vary with the deposition rate of the material.

These cost variations can be summarized as follows:

  • Flux cored arc welding (FCAW) 8 to 25 lb/hr
  • Shielded Metal Arc Welding (SMAW) 3 to 5 lb/hr
  • Gas Metal Arc Welding (GMAW), including both gas-shielded and open arc welding 5 to 12 lb/hr
  • Oxyfuel Welding (OFW) 5 to 10 lb/hr

 

Applied materials commonly include cobalt based alloys such as STELITE, and nickel based materials like chromium carbide alloys. More advanced materials such as complex carbides containing columbium, molybdenum, tungsten, or vanadium can also be used and provide more overall abrasion resistance. They also have a very low friction factor, which can be used in situations involving severe abrasion.

Hardfacing can be applied to both newly manufactured pieces, in order to prevent deterioration, or to strengthen and extend the life of worn pieces currently in use.

Red-D-Arc provides welding machines suitable for hardfacing using techniques including SMAW, FCAW and GMAW.

Is Gas Welding Really Cheaper?

13 April, 18 4:54 pm · Leave a comment · reddarc
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Oxy acetylene welding torch

The answer is often no, and here’s why…

Gas (oxy-acetylene) welders used to be the rock stars of welding. From shipbuilding to automotive manufacturing to steel forging, but that was then. Arc welding is a modern welding method that outmatches gas welding in almost every respect.

Weld finishing:

Arc welders use electric current generated by a transformer or a generator to produce a uniform, clean welds that almost never require finishing. This is not the case with gas welding. Gas welding operates using the heat generated by the ignition of a gas mixture (oxygen and acetylene) to melt the welding material or to simply fuse two parts together. This process often results in a bad surface finish. Gas welding can require additional work involving hours of grinding and polishing the welds.
(more…)

The Importance of Welding Surface Preparation

28 March, 18 2:08 pm · Leave a comment · reddarc
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By guest blogger David H.

welding surface preparationHaving worked in shipyards for seven years, I’m familiar with how dirty this type of job site can be. Ship repair worksites and welding surfaces are often filthy with rust, dust and other contaminants. Even in shops and yards where fabrication is ongoing, cleanliness is often lacking. If fabricated or refurbished pieces are being installed onboard, the surface to which the piece will be welded could be rusty, coated with scale, or have other types of corrosion.

It is hard to overstate the importance of having a clean surface when welding. Welds made on unclean surfaces can become contaminated and fail; this is especially true with certain metals, such as aluminum, and certain types of welding, such as TIG, but for all welds at least some level of cleanliness is important.

Methods and Equipment

There are numerous methods available for cleaning surfaces. The most basic are simple wire brushes and scrapers; these are ineffective beyond removing common dirt and simple surface contamination. Some hand-held tools, such as grinders and reciprocating needles are slightly more effective.

A surface that is properly prepared by blast cleaning can help you ensure fewer problems with weld quality.

Deeper cleaning processes can help to ensure high-quality welds. This is particularly important where a failed weld could be costly or create shipboard dangers for the crew. For corroded or contaminated surfaces something stronger is required. Some of the best systems available are blast cleaners. Red-D-Arc has a number of blast cleaning rental options. Dry-ice systems are environmentally sustainable, non-destructive, and use inexpensive, readily available dry-ice pellets. Recycled glass systems, which reduce dust by as much as 95% compared to dry-blasting, are available too.

Take a look at our selection of  rental blast cleaners which can powerfully clean up the dirtiest weld surface. A surface that is properly prepared by blast cleaning can help you ensure fewer problems with weld quality.

Smoke Extractors: Remove Fumes and Add Value

01 March, 18 2:11 pm · Leave a comment · reddarc
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Welding Smoke Impacts Welder
By guest blogger David H.

How important is it to remove welding smoke from the work area? Ask a welder, or ask someone who has to work in the vicinity of welders working in enclosed or semi-enclosed areas.

I recall some years ago working on a Navy general cargo ship. The ship was was undergoing extensive renovations and the hold of the had four or five levels. My employer, a small repair yard in San Francisco, unfortunately did not take air quality in the work area seriously. There were more than 20 of us working in the hold, and some number of us were welders. From a distance you could see where the work was being done — smoke and fumes drifting up out of the hold! In those days, safety requirements weren’t always top of mind. OSHA and other regulations aside, taking care of your workers by providing a safe work environment is simply the right thing to do. Without them your business can never be profitable. By failing to provide a safe workplace, you may lose workers due to health issues and employee turnover or face consequences for not complying with standards.

“respirators are hot and uncomfortable, and many welders simply refuse to use them”

There are a number of ways to deal with welding fume issues. One approach is the use of respirators. I often wore one, but they are hot and uncomfortable, and many welders simply refuse to use them. They can be remarkably expensive, over the long haul,  given that filters must be replaced daily.  If the mask is a disposable type, the entire mask must be replaced daily.

Portable smoke extractors – sometimes referred to as smoke eaters – are a far better solution. They extract a higher percentage of the fumes than respirator masks and protect everyone in the work area, not just the welders. They can be moved around the job site and from one job site to another, but can also be set up at permanent work stations.  These machines can help make sure that your work space is a place where people can get their work done safely. Your employees will thank you.

To view the smoke extractors Red-D-Arc offers for rent head over to our smoke extractor rental page.
We also have used smoke extractors for sale on our used equipment page.

Fast, Efficient Flux-Cored Welding with Semi-Automatic Wirefeeders

29 January, 18 2:43 pm · Leave a comment · reddarc
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Flux cored welding with semi-automatic wirefeedersBy guest blogger David H.

Some years back I was working in a shipyard in San Francisco. The yard had several small repair jobs going, plus a fairly large project building six ocean-going barges. The supervisor who was in charge of the barge-building project was looking for volunteers to operate semi-automatic wire feeders, using flux-cored wire, to weld stiffeners to the skin of the barges. I had never used a wire feeder before, so I volunteered out of curiosity.

After a very short training period, possibly all of 30 minutes but I think a bit less, I was off and running. I was impressed by the quality of the welds and the speed at which they were deposited. Without question I was outpacing anything that could be done by stick welding, and I felt it was easier to maintain a uniform weld size too. The machine itself was light enough and small enough to move without difficulty, and the spools of wire lasted long and were quick and easy to replace when the spool of welding wire was finished.

Red-D-Arc has nearly a dozen semi-automatic wire feeders available for almost any application. We also carry fully automatic wire feeders, which are faster still and appropriate in certain circumstances – like building storage tanks –  especially for large-deposition welds.

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