A HIGH TEMPERATURE INTERNAL FRICTION STUDY OF THE RARE EARTH ELEMENT IN 16MN STEEL

Abstract
Five kinds of specimens of 6Mn steel were contained a small amount of Cerium of different contents (1,0 ; 2,0.028wt% ; 3,0.050wt% ; 4,0.12wt% ; 5,0.083wt%). An internal friction peak near 600 °C (f=0.65Hz) was observed with torsion pendulum. The activation energy of this peak was found to be about 2.5eV, which the specimen contained Ce element after Carbon and Nitrogen were removed. But no peak was abserved which the specimen did not contain any rare earth element. It was abserved that the peak of specimen, containing some rare earth element, either appeared or disappeared with the different heat-treatment procedure. The microanalysis with EPMA showed that 0.308wt% was the content of Cerium element in the grain boundary area where no inclusion existance, on which the X-ray was irradiated. Based on the characters of internal friction peaks in this work and the former researches of the rare earth internal friction, it may be concluded that the peaks are the solid solution peak of Cerium element in 16Mn steel. The mechanism of the solid solution of Cerium in 16Mn steel will be discussed.