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Supporting Maintenance at the Grand Coulee Dam

04 June, 19 2:09 pm · Leave a comment · reddarc
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Grand Coulee Dam interioOriginally built in the 1930s, the Grand Coulee Dam in Washington State has been undergoing a series of maintenance projects to ensure that it will continue to produce safe and reliable power into the future. One stage of the project required the heating of a 40-ft wide, 7-ft tall outer head cover of the turbine shaft to a specific core temperature.  In order to achieve this temperature, the engineers applied induction heating to one side of the workpiece. Only when the opposite side of the workpiece reached target temperature could the maintenance engineers be certain that the required core temperature had been achieved.  The team from Red-D-Arc provided induction heating systems and assistance with training and set up during this essential part of the maintenance process.

More than equipment

Red-D-Arc brings more than equipment to each project; it partners with customers to provide helpful insights into the unique challenges that each project presents. Red-D-Arc associates have many years of experience supporting customers involved in energy related projects including hydroelectric, wind energy and nuclear power. Red-D-Arc’s induction heating experts are highly respected for their innovative approach to induction heating technology applications.

 

Induction Heating vs Other Methods

29 April, 19 4:48 am · Leave a comment · Colin Brown
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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.

What is Induction Heating?

Induction heating is a heat treating process that, when used properly, can alter the mechanical properties of a weld and its adjacent base metal in a way that meets the demands of the application in which the weld is being used. Induction heating relies on the science of electromagnetism to heat the part. Induction coils are placed around the material being heat treated, and alternating current is fed through them. This alternating current going through the induction coils creates a rapidly alternating magnetic field.

The eddy currents that occur as a result of this heat the material surrounded by the coils. Magnetic materials are even more easily heated by the alternating magnetic fields.

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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.

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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.