Laser welded structural sections in stainless steel are getting more and more recognized and accepted in the nuclear applications when corrosion resistance is an issue.
In the past, there was a lot of scepticism towards this performance. Also, a lot of questioning was raised about the quality, the execution and the reproducibility of the weld. Even though all hard facts were in favour of the laser technology, the execution was always kept far from the nuclear core and the primary circuits.
Seldomly, it has been used for stainless steel platforms of the buildings.
This mindset has changed recently. A first step in this direction was the use of stainless steel laser welded structural sections as stiffeners for strainers. Next it was used for strategic valves supports. And after that as stiffeners for waste water ponds and secondary circuit pressure vessels. Finally laser welded sections have been chosen as structural basement for the reactor core.
Repeated demonstrations of the quality of laser welds made this possible. Furthermore, the controls demonstrating the weld steadiness were improved continuously – as well as underlining the advantages of laser welding. First on the list would be reduced distortion. This improvement grants high precision on tolerance. That can only be achieved with big efforts when using conventional welding methods. By this, significant ease in assembly of the structur is granted.
Montanstahl employees of the quality department attended specialised training courses. They qualified successfully as 2nd level operators for visual, dye penetrant and ultrasonic inspection.
These non destructive testings (NDT) have almost become a standard test method. It is regularly required when it comes to the evaluation of laser welds for nuclear applications.
In addition to these controls it is common procedure to supply sections with raw material. Those were produced by chosen suppliers with specific characteristics as far as chemical composition is concerned.
Montanstahl is able to grant a full service package. It can be combined with production witnessing within a production quality plan of the customer. With this service Montanstahl enables new opprtunities to engineers and designers. Because standard or even tailored laser welded stainless steel sections within nuclear applications are possible now.