Heat Treatment Equipments
Heat Treatment process is commonly referred to as stress relief, so called because it is carried out at temperatures at which yield strength has fallen to a low value. If the structure is heated uniformly, the yield strength of the material around the weld is unable to support the initial deformation.
Creep occurs at the elevated temperatures and strain will occur by a diffusion mechanism, relaxing the residual stresses even further. The extent to which residual stresses are relaxed will depend on temperature for any given material and on material for any given temperature. The stress distributions at the higher temperatures become more uniform and their magnitude reduces to a low level.
On cooling, provided it is carried out in a controlled manner, the improved stress distribution is retained. In addition to a reduction and redistribution of residual stresses, post weld treatments at higher permits some tempering or aging effects to take place.
These metallurgical changes are very beneficial in that they reduce the high hardness of the as-welded structures, improving ductility and reducing the risks of brittle fracture. Post weld heat treatment has mandatory significance governed by the national standards and codes, as well as being required to offer acceptable component life in onerous environments. As with preheat, the alloying content of the steel is related to the significance of heat treatment temperature.
PWHT TECH Heat Treatment Modules include our unique â€˜Advantage has been constructed to provide power to electrical resistance heaters. Suitable for onsite and shop working.