Precipitates and Hydrogen Permeation Behavior in Vanadium-Bearing Microalloyed Low Carbon Steel

The precipitates and hydrogen permeation behavior were studied in the low carbon steel for enameling. During the preparation of samples, Ti containing and Ti free in vanadium-bearing microalloyed low carbon steel heating at 750 degrees C for 3 h, were adopted after cold-rolling. It was found that the a large number of fine VC, TiC, TiN and Ti(4)C(2)S(2) precipitates were in samples of Vanadium-bearing microalloyed low carbon steel with Ti element. And fine VC, Fe(3)C and MnS precipitates were in steels without Ti element. So the numbers of precipitates in the former is more bigger than the later. The activation energies for hydrogen diffusion in both samples are 26.5 and 23.7 kJ/mol, respectively. But at 25 degrees C, the effective diffusion coefficients in the samples for Ti containing and Ti free in Vanadium-bearing microalloyed low carbon steel were measured as 2.71x10(-6) and 4.22x10(-6) cm(2)/s, respectively. No fishscaling defect occurred in the former and heavy fishscaling defect in the later.