Abstract: Five kinds of specimens of the Pure iron containing phosphorus were used in this work. After having removed carbon and nitrogen, we measured internal friction of these specimens at a temperature range from 300℃ to 800℃ with the inverted torsion Pendulum at low freguency·Consqu ently five specimens containing phosphorus contents at a range from 0.007 wt% to 0.28wt% show two internal friction peaks at about 580℃ and about 470℃ respectively. The activation energy of this peak at about 580℃ is 2.13ev, the another is 1·80ev. After quenching at high temPeratur e, two Peaks disappeared. Based on the results mentioned above, the Peak at about 580℃ is likely the Fe-P Peak (SS Peak) and the another is Probably the Pure iron Peak (PMPeak).
Finally, the specimen of Fe-Ce-P alloy containing a small amount of rare earth element Ce was made a experiment. Three Peaks were found at about 703℃, 601℃ and 500℃ respectively. We have a tentative idea that these three peaks are the Fe-Ce SS peak, the Fe-P SS peak and the Pure iron peak (PM peak) respectively. It is remarkable that the PM peak temperature in the Fe-Ce-P alloy is higher than that one in the Fe-P alloy. The work, which a small amount rare earth element affects the internal friction of Fe-P alloys, is being perfected.