We are currently offering 2 sets of completely refurbished welding rotators (500 Tonne).
- Carrying Capacity 500T
- 2 Complete Systems Available
- Delivery Time 10/12 Weeks
- 3 Month Warranty Included
Contact your local Red-D-Arc branch for more information.
Stainless steel contains a minimum of 10.5% chromium which imparts it corrosion resistance by forming an oxide layer on the surface. The most common stainless steel is the austenitic type (300 series) which contains chromium and nickel as alloying elements. Other types include ferritic, martensitic and duplex stainless steels. Most stainless steels are considered to have good weldability characteristics. Most common processes used for welding stainless steel are TIG (GTAW) and MIG (GMAW). But, stick welding (SMAW) is also utilized.
Differences in Properties:
The properties of stainless steel differ from mild steel, and these differences need consideration when welding as below:
- Higher coefficient of expansion, 50% more for austenitic – this results in more distortion
- Lower coefficient of heat transfer – welding requires lower heat input as it is conducted away slowly
- Lower electrical conductivity – using the correct and consistent stick-out distance is more critical when using MIG/TIG, higher wire speed for the same current is required when MIG welding
Why segregated work area?
Welding of stainless steel is carried out in a work area segregated from carbon steels. Moreover, tools dedicated for use with stainless steel must not be used to work on carbon steels. These tools include brushes, hammers, clamps, grinders etc. The segregation of work area and tools safeguard the contamination from carbon steels, which may cause welding defects and corrosion (rust) on stainless steel. You must also wear gloves when working with stainless steel as this will prevent oil from the hands passed onto the stainless steel.
Preparation is key!
With stainless steel, it is important that the joint surfaces are thoroughly cleaned before welding to remove any dirt, grease, oil etc. The filler wire also needs to be completely clean.
Additionally, the joint design including the joint gap must cater to the higher expansion rate of stainless steels.
Filler Material Selection:
Filler materials used generally are the same as the base metal. Special considerations are required to select a filler material if welding dissimilar stainless steels or stainless steels where no identical filler material exists. Furthermore, filler materials are selected to reduce the risk of intergranular corrosion and hot cracking.
It is essential to protect the weld during welding using a mainly inert gas. Additionally, the weld root needs to be purged using a pure inert gas.
When welding austenitic stainless steels, it is important to restrict the heat input to a level which is just sufficient to ensure a good weld. The interpass temperature is limited to 350 F. Preheating is not carried out on austenitic stainless steels. Very low carbon grades (suffixed with L e.g. 304L, 316L) are used to prevent the formation of chromium carbides in the heat affected zones which causes intergranular corrosion.
Martensitic stainless steels are generally used as wear resistant materials in overlaying applications. To avoid cracking, accurate preheat needs to be applied and a minimum interpass temperature maintained.
Ferritic stainless steels are used mostly in automotive applications. The heat input in these steels during welding needs to be limited, and a maximum interpass temperature of 300 F is recommended. This will ensure that the grain growth in the material is controlled and the strength is maintained.
With duplex stainless steels, the heat input also needs to be restricted.
Cleaning and Passivation:
Stainless steel welds must be cleaned and passivated after completion to ensure corrosion resistance and good appearance. This is performed manually by mechanical (brushing, grinding, blasting), chemical (applying pickling agents and other chemicals) or electrochemical means.
Red-D-Arc has a wide range of equipment suitable for stainless steel welding for rent including the following:
Multi process welders capable of stick, TIG, MIG, submerged arc, air carbon arc cutting, flux core, up to 1500 A
MIG welding units up to 750 A
TIG welding units up to 750 A
Stick welding units – up to 625A
Also 4 and 6 Paks of welders available
Orbital welders – suitable for stainless steel pipe/tube welding
Various brands including Miller, Lincoln, Red-D-Arc
Have a look at our complete range of welding products.
A Red-D-Arc customer recently won a large naval defense contract that would require a substantial amount of hard automation equipment. This shipbuilding company was able to leverage Red-D-Arc’s Welderlogistics Lease program to acquire new weld automation equipment for the duration of the defense contract. With the help of over 200 pieces of leased equipment now in their fleet, this customer has grown their business considerably, and without the need for large capital expenditure.
Leasing equipment has many advantages for organizations that want to expand their business by bidding on large contracts, without the risk of tying up capital in depreciating equipment. All leased equipment comes with a full factory warranty for the duration of the contract and will be repaired or replaced without charge in the event of breakdown.
Contact us today to learn more about growing your welding fleet through our leasing program.
We carry a range of welding positioners, column and boom sets, rotators and other weld-automation equipment.
Red-D-Arc was featured in the December/January issue of Tank Storage Magazine in an editorial titled “Rental welding equipment for storage tank fabricators”. Tank Storage Magazine is an industry leading publication, reporting exclusively on the bulk liquid tank storage and terminal sector.
The storage tank construction industry is highly competitive and fabricators gain a significant advantage by leveraging Red-D-Arc’s rental fleet of automatic tank welding equipment. Red-D-Arc supplies specialized automatic storage tank welding equipment to companies in the tank fabrication industry for projects all over the world.
Along with our specialized tank welding equipment comes a highly knowledgeable and experienced team of Red-D-Arc technicians. Sayer Hendricks – storage tank welding equipment specialist at Red-D-Arc is quoted in the article: “A fabrication company without prior knowledge of the equipment, is able to rent a turn-key tank welding automation system and increase their welding productivity by 40-50%. With on-site training, service and support, our customers are up and running quickly and making 100% x-ray quality welds without fail”
The full article is available here: Rental welding equipment for storage tank fabricators
By guest blogger David H.
Having 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 cleaning 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.
Red-D-Arc will be exhibiting at Tube Düsseldorf trade show in April. Be sure to drop by booth 6F23 in Hall 6 to view our latest pipe welding and cutting equipment.
Red-D-Arc offers a comprehensive selection of pipe welding equipment for rent.
Importance of Preheating in Welding – Equipment Options
Preheating reduces the risk of cracking in weld metal and heat-affected zone (HAZ) by:
- Lowering the cooling rate of the weld – prevents formation of brittle weld metal/HAZ, allows more time for hydrogen to escape the molten weld.
- Removing moisture (hydrogen source) from the part.
- Reducing shrinkage by lowering the temperature differential.
Preheat or not?
The requirement and level of preheating for steel is determined by the relevant welding code and is dependent on the weld heat input, chemical composition of steel (carbon equivalent), thicknesses, diffusible hydrogen etc. Non-ferrous materials generally require preheat because of their high thermal conductivity.
We have a number of reconditioned used welders available for purchase including:
- TransPulse Synergic TPS 5000 MIG/MAG Package with wirefeeder and cooler
- Miller Maxstar 200 Autoline – Stick, TIG, Pulsed TIG, Air Carbon Arc Cutting
- Lorch T-300 TIG Welder – Stick, TIG, Pulsed TIG
Each of these welding machines comes with a 90 day warranty.
View our flyer for details.
Fronius TransTIG 1750
Miller Maxstar 200
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 undergoing extensive renovations and the hold 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.
By 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.