What We Offer

Stress Relieving

Stress relieving is a heat treatment process in which a metal is subjected to a constant temperature that is below the metal's critical temperature, followed by controlled cooling.

Drawing, forming and machining induce stresses in materials. A stress relief operation is typically used to remove internal (residual) stresses that have accumulated in the material. These stresses can cause loss of tolerance, cracking and distortion and contribute to in-service failures. For these reasons, stress relieving is often necessary or even mandatory.

The stress relief process is performed by heating in an oven or furnace to a temperature below the critical temperature (different materials have different temperatures) and holding it at that temperature long enough to achieve the desired reduction in residual stresses. Temperature, time and time held at the temperature are key process variables, if necessary stress relieving can be performed in a furnace with protective gas, to protect surfaces from oxidation. In extreme conditions vacuum furnaces can be used.

  • It relieves internal stresses without causing any color change.

  • Welded structures can be made tension free by stress relieving.

  • It removes internal residual stresses from steels. The stresses may have come from the steel making mills, machining, forming, welding etc.

  • Typical parts that benefit from stress relieving are large and complex welded assemblies, castings with a lot of machining, parts with tight dimensional tolerances and machined parts that have had a lot of stock removal or rapid stock removal.

  • Many heat treatments and welding processes cause stresses in the material that can lead to warpage either after the heat treating process or during subsequent machining operations. Of specific concern is the stress induced by welding. If a weldment is to be machined it should almost always be stress relieved before the machining process. This is because machining chunks of material from a stressed weldment redistributes the internal stresses and can cause the part to warp. If the stresses are first relaxed then abrupt changes in geometry after machining are reduced.

  • Machining induces stresses in parts. The bigger and more complex the part, the more the stresses. These stresses can cause distortions in the part long term. If the parts are clamped in service cracking could occur. Hole locations can change causing them to go out of tolerance. For these reasons, stress relieving is often necessary.

Maximum Sizes & Capacity

 

  • 900 mm width x 460 mm height x 1,100 mm length

  • 300 KG - 800 KG maximum load

 

Allow 48 hours, however extraordinarily large jobs may take longer.

 

Urgent work is subject to load size and discussion with our Customer Liasion Department.