Abstract
This paper describes the experiments of the sliding tests of the alloys for the large size gate valve seats materials used at high pressure and high temperature. The four grade Plasma Transfer Arc welding powders have been made as laboratory scale and 23 kinds of seat specimens also have been made using these powders. Sliding tests have been done combined with the already existed Ni base hard facing alloy which has 529 to 613 HV hardness as disc specimens in 293K, 473K and 573K pressurized water. The test method simulates the gate valve. It is clarified that the Ni alloy which contains iron about 40% shows the good sliding property, good pressure tightness and also shows the good mechanical properties as the gate valve seats material.
