2026-10-14T18:42:30Z https://www.scidb.cn/oai

10.57760/sciencedb.39830 2026-06-22T15:45:50Z

2026-06-22 Effect of Solution Temperature on Microstructure and Wear Resistance of Stellite 6B Alloy doi:10.57760/sciencedb.39830 en Cobalt-based Stellite 6B is a wrought alloy with excellent wear resistance combined with guaranteed mechanical properties such as tensile plasticity and impact toughness. Considering that there is a certain risk of radioactive contamination from the cobalt bearing debris in the nuclear reactors, the design of the grippers requires that the wear loss of the grippers made of the cobalt-based stellite alloys should be controlled to a critical mass during the srvice life-time, and also requires to ensure the material with tolerable mechanical properties simultaneously. Many studies have shown that under determined frictional conditions, the wear resistance and mechanical properties of stellite alloys highly depend on their microstructures. Therefore, it is necessary to investigate the microstructure variations and subsequently wearing resistance and mechanical properties of the employed Stellite 6B after solution treatments at different elevated temperatures. In this paper, the microstructure details of the Stellite 6B alloy solution treated at temperatures ranging from 1000℃ to 1200℃ were observed by SEM back-scattered electron images and electron back scatter diffractions in scanning electron microscope and TEM techniques. Then, the alloy’s hardness and impact toughness were evaluated, and at meanwhile, 107 whirl wear loss of the friction pair of the studied alloy against to GH5605 alloy were measured by block on ring sliding wear test method. The microstructure observation and mechanical tests indicate that the Stellite 6B alloy presents an uniform and fine grain matrix and equiaxed primary M7C3-type carbides after solid solution treatment at 1200-1150℃ and exhibits favorable impact toughness. While, as the solid solution temperature decreases, increasing amount of secondary M23C6 carbides precipitate mostly along the grain boundaries and consequently increase the hardness slightly but depress the impact toughness sensibly. The fracture surface observation confirmed that the continuity of grain boundary carbides is the main microstructural factor leading to the decrease in impact toughness. Wearing test results showed that the average friction coefficient gradually decreases as the solution temperature decreases. Meanwhile, 107 whirl wear loss of the studied alloy decreases a little when lowering the solution temperature from 1200℃ to 1150℃ and notablely drops by more significantl amount as reducing the solution temperature further. Then, it is good to identify that the solid solution treatment at 1100℃ can endow the Stellite 6B alloy with excellent wear resistance and tolerable impact toughness. The back-scattered electron images and EDS analysis of the worn surface indicate that after the wearing test, the surfaces of the friction pair alloy GH5605 are covered with a large amount of Stellite 6B alloy debris, demonstrating that the major wearing mechanism of the two cobalt based alloy mating pairs is adhesive wear. The electron back scatter diffraction patterns of the worn samples showed high density dislocations in the outer layer that induces certain amount of hcp structure ε phase in the metastable fcc structured matrix. It is noteworthy that the amount of ε phase is rather significant in the worn samples solution-treated at 1100℃ or lower temperatures but only minute quantity of ε phase is visible in TEM observation. This suggest that the cumulative strain can induce the martensitic transformation in the metastable fcc structured matrix of lower temperature solution-treated samples, so that the improved anti-adhesive wear performance of the Stallite 6B alloy can be attributed to the increased amont of hcp structure ε phase in the matrix ever solution treated at lower temperatures. Stellite 6B alloy; solution temperature; microstructure; impact toughness; sliding wear Zhang Yawei Liu Hao Shen Yu Ren Pengwei Wang Yunxia Ju Quan Xu Guohua Zhang Ji PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset Science Data Bank