DECOMPOSITION AND PRECIPITATION OF CARBIDES IN HOT-ROLLED Si-Fe SHEETS

The decomposition and precipitation of carbides in the hot-rolled Si-Fe sheets were studied by means of both high temperature metallography and differential thermal analysis. It has been found that the decomposition during heating and the precipitation during cooling start from 720 and 750℃ respectively. The shape and distribution of the precipitated carbides are markedly influenced by the cooling rate of the sheets after hot-rolling. If the cooling rate is high enough, saying up to 100℃/min, the carbides would be precipitated dispersely; while it slows down to about 1℃/min, they would be aggregated coarsely. The shape and distribution of the precipitated carbides are dependent on the efficiency of decarburization. In other words, the more disperse the carbide is, the more effective the decarburization will be. The results may provide leads for further improvement on the technology for hot-rolling Si-Fe sheet production.