Delta Heat Services is a specialist in heat treatment services on site. With our flexible approach and high quality services we can manage mayor turn arounds and new build projects in the industry, large constructions works and maritime. We are specialised in preheat, annealing, post weld heat treatment (PWHT), bake outs, dry outs and shrink fittings.

Preheat is done to raise the temperature of the parent steel before and during the welding process. This is done to slowdown the cooling rate of the weld and the base material to avoid expanding and shrinking of the heat affected zone. This will result in a better weld metal and the heat affected zone microstructures.

Post weld heat treatment (PWHT) is done after the welding process to improve the properties of the weld. Depending on the material and usage of the workpiece, we work with different heat treatment procedures according to client standards. During the welding process a high temperature is experienced in the weld and parent metals. Once the weld cools, a residual stress is formed. After the PWHT process is complete, a specific procedure will be performed to reduce these stresses to an acceptable level. This also helps to reduce any increased hardness levels and improves toughness and ductility to an acceptable level.