The Effect of Boron on the Peak of Internal Friction of Low Carbon Batch-annealed Steel Produced by Compact Strip Production

摘要

Via. the comparative experiment between B-contained and B-free low-carbon annealed steels produced by CSP (Compact Strip Production) , this paper researches the effect of boron on the Kb peak and the snoek peak. Experimental results of internal friction revealed that the addition of boron makes the snoek peak move to lower temperature and reduces the altitude of peak. Boron with the low activation energy may contribute to this phenomenon these atoms decrease the relaxation time as a result, peak move to the lower temperature, and relaxation strength falls down. On the base of empirical formula and snoek peak, we approximately calculate the content of the solution carbon atom in lattice space in the two kinds of tested steel.which is lower than the value of electrolysis chemical phase analysis. It implies that more carbon can be stored in the dislocation or grain boundary than formerly expected, Furthermore , during the process of annealing, dislocation climbed, which made the density decrease , so we can concluded that the most of the rest of carbon may be stored in grain boundary in this experiment. The value of the carbon segregating to grain boundary is larger in boron tree steel. In the term of the curve of Ke peak, there is almost no difference in the internal friction temperature curves between the two tested steels, the peak can be observed at about 525C. This may be attribute to the coaction between the sise of grain, solid carbon, precipitate and the diffusion of vacancy,the effect of boron is not notable.