Reduce, Redistribute and Restructure the residual stresses
PWHT (Post-Weld Heat Treatment) is performed usually after welding in order to ensure the material strength of a part is retained after welding. Post Weld Heat Treatment is essentially method of altering the physical and sometimes chemical properties of metals and essentially can be defined as a controlled heating and cooling of a metal or metal alloy, in its solid state, to produce certain changes in its properties.
Post Weld Heat Treatment is also known as Stress Relief Heat Treatment, which is performed by heating to a temperature as detailed in the welding code for the appropriate material, and holding at that temperature long enough to achieve the desired reduction in residual stresses. The steel is then cooled at a sufficiently slow rate to avoid formation of excessive thermal stresses.
PWHT is typically essential to reduce residual stresses, as a method of hardness control, or even to enhance material strength.
With a fleet of over 50 PWHT machines, we bolster our specialty services. With a team of highly skilled and experienced PWHT technicians, we serve customers in fabrication and heavy steel industries.
TYPICAL CYCLE OF PWHT
Typical cycle for ASTM A 106 Gr. B
- Heating Rate: 200°C/Hour
- Soaking: 600-620°C for 1 Hour
- Cooling: 200°C/Hour
ADVANTAGES OF PWHT
- Improved ductility of the material
- Improved metallurgical structure
- Improved or reduced hardness
- Reduced risk of brittle fracture
- Relaxed thermal stress
- Tempered metal
- Removal of diffusible hydrogen (to prevent hydrogen induced cracking)
OUR CORE SERVICES INCLUDE:
Inspection, testing and endorsement services for various industries
Conventional and Advance NDT Services
Asset Integrity Management and Field Inspection Services
Post-Weld Heat Treatment (PWHT) Services
Mechanical and Welding Qualification Testing
Metallurgical Failure Investigation
Corrosion Investigation and Testing
Analytical Chemical Testing
Rope Access for inspection at heights and "Normally difficult to Access" locations.
Our services are indispensable for the process owners and help them decide the course of action related to their materials, equipment, components for qualification and continued usage through our core services.
OVER THREE DECADES OF PROFESSIONAL EXCELLENCE
Analytical and Technical Laboratory in the Middle East having Metallurgy, Mechanical Testing, Chemical Testing,
NDT, Marine Survey, Field Inspection, Asset Integrity Services and PWHT facilities all under one roof that employs over 100 professionals. And Versatile Integrated Quality Management System and International Approvals.