Corrosion behavior of LaFe_(13-x)Si_x system compounds

摘要

The corrosion behavior of LaFe_(13-x)Si_x alloys were studied in this paper. The materials was prepared by arc melting and annealed at 1623K for 3 h. X-Ray diffraction (XRD) and scanning electron microscope (SEM) show that the. NaZn_(13) type phase is the main phase, a-Fe is present in form of globular grains while the LaFeSi phase is distributed along the grain boundaries of the main phase. The SEM shows that the phase containing more lanthanum corrodes faster than other phases. La_2(CO_3)_3·H_2O_8 was formed due to the existence of CO_2 in the solution in the open system, and Fe(OH)_3 was deposited on the bottom of bottle after 168 h immersion. H_2C_2O_4 and NaOH were used to adjust the pH value, and the result show that the corrosion current of LaFe_(11.6)Si_(1.4) alloy in alkaline solution is smaller than that in acid solution.