Tribological characteristics of rolling bearings in high-temperature, high-pressure water

摘要

The Japan Atomic Energy Research Institute (JAERI) is currently working to devdop an advanced integral type marine reactor, MRX, for use in ship propulsion or nuclear energy supply. The MRX adopts an in-vessel type control rod drive mechanism (CRDM) which is placed inside the reactor vessel to eliminate the possibility of control rod ejection accidents and to make the reactor compact. Bearings of the CRDM should be able to function in high-temperature, high-pressure (320℃, 11.8Mpa)water. In order to survey corrosion resistance, wear resistance and other tribological characteristics of the bearing in such a severe environment, rolling testing using test specimens made of various materials was conducted at a rotational speed of 1 85min{sup}250L?1） and a load of 440N in high-temperature, high-pressure water. The test results showed that the combination of cobalt alloy or cermet rings, cermet balls, and a graphite retainer gave superior hearing performance. Graphite and metal oxide are considered to have acted as lubricants and contributed to reduce wear significantly for bearings in high-temperature, high-pressure water.