Development of Understanding of the effects of Laser Cladding on Novel Iron- Based Hardfacing Materials

Nuclear power plants are complex engineering structures with a multitude of different components required to make them operate. One area that rarely hits the headlines, but it fundamental to the operation of the plant, is tribological components such as valves and pumps. These components operate in a particularly aggressive environment of a high neutron flux, high load contacts and lubricated by just superheated water. Traditionally, there has only been one material that can survive this highly hostile environment: cobalt based hardfacing alloys called Stellites. However, there is a big problem with these alloys. The exposure of cobalt to a neutron flux results in the formation of cobalt-60 radioisotope, which causes radioactive exposure by site workers and contributes to radioactive waste. The obvious answer to this problem is to remove the cobalt from the hard facing. This is a very challenging materials problem. Our hypothesis is that iron based alloys can be designed that will meet the performance standards of the current Stellites. The project will look at recently invented Fe base alloys processed through a novel laser deposition manufacturing route. The microstructures and friction and wear behaviour will be studied in detail to input into further alloy development.