Magnetic Properties and Corrosion Resistance of (FeNiCr)_(80)P_(20) Amorphous Alloys for Filtering Media Use

摘要

With the object of developing a ferromagnetic filtering media used in electromagnetic filtering process of iron & steel industries, addition effects of Cr and Ni on magnetic properties and corrosion resistance for Fe_(80)P_(20) amorphous ribbon alloy have been investigated. In (FeCr)_(80)P_(20) ternary alloys, the soft magnetic properties and corrosion resistance were largely enhanced upon Cr addition of about 5 at percent, although considerable decrease in saturation magnetization occurred. However the corrosion rate was thought to be still high for practical use. If the Fe was substituted by some Ni to form a quarternary Fe-Ni-Cr-P alloys, decrease of the saturation magnetization was strongly suppressed. Moreover the soft magnetic properties and corrosion resistance were improved to a great extent as compared to Fe_(75)Cr_5P_(20) amorphous alloy. For Fe_(75)Ni_5Cr_5P_(20) amorphous alloy, the values of B_(10), M_s and H_c were 6.9 kG, 110 emu/g and 0.24 Oe, respectively. The corrosion rate was measured to be very low(less than 0.2 min/ in 5 wt percent HCl solution(room temperature) and 2 wt percent NaOH solution(60 deg C). The good soft magnetic properties and corrosion resistance of Fe_(75)Ni_5Cr_5P_(20) amorphous alloy were attributed to the decrease in saturation magnetostriction and more active formation of CrO_x(OH)_(3-2x) centre dot nH_2O passive films by the combined addition of Ni and Cr.