In welding, like in many other manufacturing and fabrication processes, the process is not complete until the necessary post-processing has been carried out. Post-weld operations are usually performed for reasons such as improving mechanical properties, relieving stress, and improving aesthetics. The two most common Post-weld operations are Post-Weld Heat Treatment (PWHT) and Finishing.
Post-Weld Heat Treatment
During welding, the welded materials are exposed to very high temperatures that can cause micro-structural changes in them. Also, residual stresses build up in welded materials when they are allowed to cool naturally. If left unaddressed, these stresses and structural changes can severely compromise the mechanical properties of a material and can lead to failure during use. To prevent this, PWHT is required for welded parts. There are two major types of Post-weld heat treatment and they are as follows. (more…)
Quality Assurance (QA) is a set of defined processes for systematic monitoring and evaluation to assure product quality.
Quality Control (QC) is the process of confirming that the product meets the specifications. It includes the checking and testing of manufacturing procedures as well as the final products. The results from these tests are compared with a set of defined acceptance criteria. By carrying out QC testing during manufacturing, defects can be identified in a timely manner, allowing for the product flaw to be rectified and if required, adjustments to be made in the manufacturing process to prevent further defective output.
In welding, QA/QC plays a vital role in ensuring sound and reliable welds are produced and in minimizing rework. (more…)
The manufacturing industry is in distress. There is a shortage of skilled talent and this gap is only widening. While manufacturing companies are able to make goods faster and cheaper than ever, there is a growing lack of skilled manufacturing employees to ensure that production continues. Industry projections from Deloitte and the Manufacturing Institute, among other industry analysts, predict that over the next decade, more than 2 million manufacturing jobs will go unfilled across the U.S. (more…)
Pre-weld and post-weld heat treating is critical for many welding operations. Without proper thermal manipulation, welds and heat affected zones can have mechanical properties that are undesirable. Worse yet, inadequate heat treatment can result in cracks and devastating weld failures. While temperature and time are the primary concerns when heat treating a weld, the heating method should also be considered diligently when selecting a process. Induction heating is one of the most popular types of heat treating methods, and rightfully so. The benefits of induction heating are many, and Red-D-Arc has the equipment you need to successfully implement an induction heat treating operation for your projects. (more…)
In industry, a growing trend is the idea to use orbital welding as a solution to the mounting problem of welder shortages. It is a well-known fact there are just not enough pipeline welders to go around (no pun intended). By 2020, the American Welding Society expects the U.S. will face a shortage of 290,000 welders. Companies in other business sectors — from food service companies to banks — attempt to solve labor issues and increase efficiencies by utilizing automation to replace workers. Is automation, specifically orbital welding in this case, the way to improve operating factors and productivity?
Welding small diameter tubing can be difficult. The tight radii often require expert welders to deliver precise torch manipulation with finesse. If the welder is not skilled enough, the out of position areas are at risk of poor quality due to gravity affecting the weld pool and ineffective torch angles. If out of position welds cannot be completed satisfactorily, the part must be rotated. However, some assemblies can’t be rotated because of size constraints or they might rotate off of center. If a mechanized welding solution is desired for small diameter components, look no further than our Axxair Orbital Fusion Closed Welding Head Systems. (more…)
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.
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. (more…)
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.
Katarzyna has an Msc in Materials Science and has worked in the oil and gas industry in jobs related to hydraulics, welding and the retrofitting of oil rigs.
Stainless steel is used extensively in the petrochemical industry due to its high resistance to severe conditions. When welding inox steels, the smallest details matter and have an impact on weld quality. The following are some tips for stainless steel pipe welding based on my oil rig repair experience:
During an oil rig repair project that involved 2205 duplex stainless steel pipe TIG welding, we could not achieve the required weld properties. Despite using the recommended filler metal with higher nickel content, compared to the base metal, and controlling the interpass temperature, the weld tensile strength was still too low. In order to reach the required weld quality we dug deeper and found a solution – (more…)
A metal fabrication company located in Charlotte, North Carolina received an order for 300 small I.D. vessels for titanium molds. At the time they were using FCAW and back gouging the inside and outside of the vessels to achieve 100% penetration. On average they were producing 2 vessels per hour with 2 welders.
They reached out to Red-D-Arc to find a faster and more efficient way to produce these vessels. After discussions with Red-D-Arc the fabricator decided to purchase a turnkey submerged arc system. The custom designed system came complete with a small I.D. sub arc welding head mounted on a 9’x9′ manipulator, flux recovery system, NA5R automatic wire feeder, DC600 multi-process welderand 5 ton turning rolls. The system also included a laser and camera for precise control and monitoring of the submerged arc welding process.
The submerged arc system increased productivity by 250%. They were able to produce 5 cans per hour with half the labor cost. The safety of the work place was also significantly increased for a number of reasons:
• Back gouging was eliminated which in turn reduced the risk of fire
• Turning rolls replaced manual rotation of the vessels on tables
• Welders no longer had to weld inside the confined space of the vessels
The customer and the Red-D-Arc team were beyond pleased with the results. The customer plans to purchase two more of these systems for future projects.
Submerged arc welding can increase the efficiency and quality of many industrial welding projects regardless of the size or complexity. Red-D-Arc has all the equipment, expertise and experience to provide you with a submerged arc system to fit your needs – available for sale, lease and rent
“You should give as much consideration to the preparation as you do to the actual welding”
Pipe welding is utilized all around the world in diverse industries. A variety of pipe sizes and material grades are joined to manufacture components of various shapes and lengths – from a few feet to many miles. Even though most pipe welding jobs have custom specifications – there are some fundamental aspects of pipe welding that form a common thread for welders and welding engineers alike in order to achieve high quality welds in pipes.
Selecting The Right Pipe Welding Equipment
Equipment selection is the top requirement for producing good quality pipe welds. The highest priorities when selecting welding equipment for pipeline welding are reliability, consistency, accuracy and process control. It is also critical that the equipment is easy to use and the controls are intuitive. In addition to equipment performance, the work environment also needs to be a key factor for equipment selection. There are pipe welding configurations designed for offshore welding, remote land based pipeline welding, general fabrication shop use and custom configured automated pipe welding systems. Selecting the right one can be a daunting task – it is always good practice to seek expert advice. Be sure to ask about the various options, capabilities and limitations of each system. When welding CRA (Corrosion Resistant Alloy) grades, it is necessary to use weld purging in order to guarantee the corrosion performance of the root run. The importance of this should not be underestimated.
Welding inspectors have a responsibility to the company they work for and the general public to ensure that weld quality is satisfactory. Failure to fulfill their duties can result in property damage, injury, and death. Most welding inspectors, therefore, take their job very seriously. Welding inspectors spend years honing their ability to detect and size welding discontinuities and defects. While they must be proficient at identifying all discontinuities and defects, some of these weld irregularities are more readily detectable than others.
1. Surface Porosity
Porosity is gas that has been trapped in the weld; this results in cavity formation within the weld. Porosity can cause reduced weld strength. Welding inspectors who are not trained in other forms of nondestructive testing are limited to viewing the surfaces of welds. So while not all forms of porosity can be detected by a welding inspector, porosity that extends to the surface of the weld can. (more…)
Red-D-Arc carries an extensive inventory of welding equipment designed specifically for pipe welding professionals. The latest pipe welding equipment can increase productivity and produce the highest quality welds. We have an extensive fleet of innovative solutions like the Miller PipeWorx Welding System, Red-D-Arc Oscillating Pipe Welder, Bug-O Systems, Orbital Welding Systems from Lincoln and Axxair, and pipe end prep equipment from H&M and E.H. Wachs.
Welding equipment and operations can be expensive, but these costs can be lowered by making a few minor changes. Many fabricators and manufacturers are aware they have problems in their operation but struggle with quantifying the real costs associated with those problems. Some things to consider when trying to lower your costs but increase efficiency and productivity are: the type of equipment you’re using, how old the equipment is, labor costs and properly equipped welding stations.
The Airgas/Red-D-Arc Weld Efficiency Analysis program can help you find hidden costs robbing your profits. This free program helps customers understand and control the hidden costs associated with many welding operations. We will analyze your welding operations and compare your results to peer benchmarks and best practices. A three-and-a-half day class is also available, designed to help you learn from experts, reduce your operating costs by 20% or more and improve quality …all without any capital investment.
Learn more about the Airgas/Red-D-Arc Welding Efficiency Analysis program.
Earlier this year, Red-D-Arc delivered several of our MIG/MAG 4-pak and 6-pak multi-operator welding packages to Heerema Fabrication (HFG) for their yards in Zwijndrecht and Flushing, Holland. HFG manufactures complex steel structures for use in the offshore oil and gas industry.
In addition to maintaining high-quality welding standards, HFG was able to increase both worker productivity and safety by employing Red-D-Arc’s multi-operator packs for the welding processes at their fabrication yards. The packs include six welding power sources and wire feeders with gas lines to accommodate up to six individual welders – and each welder has his own 115VAC power supply as well as an airline that provides filtered breathing air to the welder’s helmet. All input power, shielding-gas and breathing-air connections are made via single connections in the pak’s enclosure in order to simplify hook up as well as enhance portability.
“With the multi-packs our operators can get set up faster and start welding immediately. The time savings and increased efficiency easily covers the cost of the packs.”
After receiving their initial order of 6-paks, HFG placed a second order for 4-paks, having recognized the benefits of the system.
Red-D-Arc 4-Pak and 6-Pak MIG/MAG Multi-Operator Welding Packages are available for rent, lease or purchase. Contact Sales to learn more.
Red-D-Arc is pleased to announce that on September 5th, 2012 AC Hi-Tech, Inc. of Cleveland, Ohio was acquired by Red-D-Arc Welderentals, a global leader in the rental, sale and lease of welding equipment, weld automation equipment and other welding-related products and services. AC Hi-Tech’s team of dedicated personnel has become part of the Red-D-Arc team, continuing to work out of their existing Perkins Avenue facility in Cleveland. They will continue to provide the same level of cutting machine equipment expertise and service that you have come to appreciate and respect. In addition to offering cutting machine sales, lease and rental services, the former AC Hi-Tech facility will also inventory Red-D-Arc’s proprietary line of rental welding equipment to better serve both new and existing customers in the Cleveland and surrounding areas. In addition to other weld-automation product offerings, the Cleveland facility will continue to offer cutting machine remanufacturing services, CNC controls, custom-built drive, motors and gear boxes, high-quality cutting and plasma machines and accessories as well as other state-of-the-art equipment to help make your company more productive.
Airgas, an Air Liquide company, is the nation's leading single-source supplier of gases, welding and safety products. Known locally nationwide, our distribution network serves more than one million customers of all sizes with a broad offering of top-quality products and unmatched expertise.