Stress-relieving is a post-weld treatment that reduces residual stresses present in a workpiece after welding. These residual stresses could cause distortion or premature failure of the joint if left untreated. The stress-relieving process involves heating the workpiece or localized area around a weld to a specific temperature, holding it at that temperature for enough time to reduce the stresses present in the material, and then cooling the material at a slow enough rate so as to not allow the stresses to redevelop. Another way to think of this process is that you are essentially annealing the welded area.
Stress-relieving can also be done using a pre-heat method prior to welding. this ensures that both surfaces to be welded are at the same temperature. Starting the parts at a higher temperature reduces the difference in temperature between the welded and non-welded areas, creating less internal tension in the weld.
Stress-relieving is important because internal stresses in the weld can result in a weaker joint that may lead to premature failure.
Induction can be useful for this process because it allows for precise heat control. This means that the welded area of a part can be stress relieved without affecting the rest of the part. In some cases, induction technology can be integrated right into the same machines or part fixturing used for the welding which can save significant time and energy when dealing with large parts.
Stress Relieving Industries & Equipment
Stress-relieving is common across most industries that utilize welding. The process is incredibly scalable and can be done using stationary coils with a moving part, hand-held systems, and even robotically mounted systems.
Pipe & Tube Manufacturing
The practice of stress-relieving welds is a necessity in the manufacture of piping and tubing. Both seam welds and butt welds must be stress relieved in order to ensure a quality product.
The voyager line of products are compact, handheld systems that make it possible to stress-relieve welds either by hand or by mounting the unit on a robotic system. The Voyager unit can be passed over the weld-affected area, or remain stationary with the part passed underneath in order to stress relieve the joint.
Flexible Rope Coil
The Flexible Rop Coil is a unique design by Radyne that allows the induction coil to be wrapped around an object before connecting it to a power supply. This makes it extremely versatile and means that it can be used on multiple different diameters and shapes of pipe and tubing. The Flexible Rope Coil can be used for stress-relieving by wrapping it around the weld-affected area and applying power.