In this weeks article, Laser metal deposition for metal seated valve components, written by Scott Poeppel, Vice President at American Cladding Technologies (ACT), we look into how there is a constant need to improve wear performance of valve components. Hardfacing overlays have been used for many decades. The more traditional methods of applying a hardfacing weld overlay, (SMAW, PTAW, GMAW, SAW, etc.) have also been used for many decades. For this discussion, ACT chose to focus on corrosion-resistant alloy (CRA) Cobalt 6 (trade name Stellite 6), as the overlay alloy since it is presumably the most common overlay for metal seated valves.
The single, largest advantage of using a laser to apply weld overlays is heat control. The focusing ability of the laser allows for very precise input, Poeppel writes. This translates to less component distortion, less welding stress, less dilution of the overlay material, smaller heat-affected zone (HAZ) at the weld interface, and less overlay material needed, since dilution is minimized.
To read the full article, please email Catarina Muia at c.muia@kci-world.com for the article PDF.