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

核电站是复杂的工程结构，有许多不同的部件需要使其运行。有一个领域很少成为头条新闻，但它对工厂的运行至关重要，那就是摩擦学部件，如阀门和泵。这些组件在高中子通量、高负荷接触和仅由过热水润滑的特别恶劣的环境中运行。传统上，只有一种材料可以在这种高度恶劣的环境中生存下来：钴基堆焊合金，称为钨铬钴合金。然而，这些合金有一个大问题。钴暴露在中子通量下会形成钴-60放射性同位素，使现场工人受到放射性照射，并产生放射性废物。解决这个问题最明显的办法是去除硬质表面的钴。这是一个非常具有挑战性的材料问题。我们的假设是，可以设计出符合当前斯泰利特合金性能标准的铁基合金。该项目将着眼于最近发明的铁基合金，通过一种新的激光沉积制造路线进行加工。将详细研究其显微组织和摩擦磨损行为，为进一步的合金开发提供依据。

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.