Blog

Induction Heating vs Other Methods

29 April, 19 3:33 pm · Leave a comment · wpdude
Share
Facebooktwitterlinkedinmail

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.

Induction Heating Equipment

Setups for weld induction heat treating can vary somewhat from application to application, but Red-D-Arc has the equipment needed for most common scenarios. Every induction heating system requires a power source. The power source converts electricity from a power grid into an electrical current that can be used to energize another critical piece of equipment in an induction heating setup: the induction coils. Induction coils are typically made out of copper and are not required to be in contact the workpiece. The power source and the induction coils are the two main components of an induction system, although other pieces of equipment such as blankets can be used to shield the induction coils and aid the heating process.

Why Use Induction Heating Over Other Heating Processes?

Induction heating has many benefits over other processes. Torch heating operations do not have the accuracy of induction heating methods. The flame heats the workpiece in an extremely varied way. Also, a torch heating operation must start with its heating on the outside and let the temperature “soak” its way into the part. Induction heating can use a variety of electrical frequencies to adjust the initial heating position within the depth of the material to some extent. Additionally, the width and length of the heated material can be adjusted precisely with induction heating, unlike torch heating.

Torch heating requires the use of combustible gases, which can be dangerous. Volatile gases can explode and cause injury to workers and destruction of property. These combustible gases also release hazardous fumes that may require respiration or fume removal, especially in confined spaces. On the other hand, induction heating, when used properly, releases no harmful fumes. Since combustible gases are not used during induction heating, there is no risk of explosion.

Another common heat treating process is furnace heating using electrical resistors as heating coils. This process can take a very long time for thick parts, and, similar to torch heat treating, works by heating the exterior surfaces of a base material first and allowing the temperature to soak into the core. Conversely, induction heat treating can be performed rapidly, potentially shaving many minutes off of a resistance furnace operation. The core can be heated much quicker as well with induction heating. Induction coils used with a piece of equipment such as the Miller ProHeat 35 are much more portable than furnace operations as well, allowing for far more practical use in the field.

While there are many advantages to induction heating and induction heat treating, there are some disadvantages. One disadvantage is part geometry. Unless an induction furnace is being used, parts will simpler geometries such as pipe or plate are more readily induction heat treated than ones with more complex geometries simply because the induction coils must be placed around the part.

Another disadvantage is that the initial cost of an induction heating system is typically more expensive than a torch heating system. However, this is where Red-D-Arc has you covered. With our induction heat equipment rentals, you can see firsthand the benefits of induction heating without large capital investment so you can keep on welding!

Welder shortage: Key is efficiency, not automation

02 April, 19 5:42 pm · Leave a comment · wpdude
Share
Facebooktwitterlinkedinmail

Note: This article first appeared in BIC Magazine

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?

The first part of improving welding operations is not to look at the welding process but instead examine its upstream aspect at material input. Material fit-up is the first key to improving quality and productivity. Poor fit-up causes overwelding and often leads to weld quality issues. A fillet weld that requires a quarter-inch weld has an unintentional root opening or misalignment of 1/16 inches. It then requires a 5/16-inch weld, which in turn increases weld joint volume by 57 percent. This result means 57-percent more wire, 57-percent more gas, 57-percent more use of consumables and — the most costly issue — 57-percent more time to weld that joint.

Let’s say that same 5/16-inch weld is then welded within tolerances, but the weld size is overwelded by 1/16 inch.  That 5/16-inch weld then becomes a 3/8-inch one due to the compounding factors of material fit-up and a very common practice of overwelding. This weld that could have been done to code and adheres to a welding procedure is now 100-per-cent more costly then intended.

Are you buying double the gas and wire you need? Eighty-percent of most welding operating expenses are in labor. What are you paying to have someone weld 100-percent more than what is needed?

What is paramount is we can create precision fit-up and limit overwelding with the use of end-prep and orbital welding. Regardless of welder skill or the type of welding equipment, starting a weld with poor fit-up will result in a weld that costs more to produce. The conversation about quality, productivity and efficiency should not start at orbital welding or about your welder’s skills but should instead begin at end-prep. End-prep equipment, simple to operate and often overlooked because of its necessity, offers machine shop-like precision and fit-up while in the field. With the unfortunate skill gap widening in the trades, it is imperative to start your pipe or tube welding with precise fit-up, as those who can make passable welds become fewer and fewer.

We aren’t replacing welders with automation; we are making them more efficient. The goal is to take the welder you have and select the proper end-prep and orbital welding process for your job so you can possibly create twice as much time for him or her and improve quality along the way.

In order to meet the rising challenge of the lack of qualified welders, we need owners and management as well as welders to come together to increase quality and productivity. Management needs to provide welders with good material and proper equipment to work with, and the welder needs to realize we aren’t attempting to take his or her job but instead attempting to give him or her the best tools to get the best result.

When you look for a company to fulfill your business’ welding needs, you should search out a supplier that offers more than just equipment. Find a supplier that offers not just a few options of welders but solutions.

For more information, visit www.red-d-arc.com, call (866) 733-3272 or email Brian Imhulse at Brian.Imhulse@airgas.com.

AirGas Logo

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.