Iron-based amorphous alloy and preparation method therefor

1. A method for preparing an iron-based amorphous alloy, comprising

preparing raw materials according to atomic percent in the iron-based amorphous alloy of formula Fe a B b Si c ;

smelting the prepared raw materials to obtain a molten steel;

adding a rare earth alloy after the molten steel achieves a target temperature in the smelting process to obtain a smelted molten liquid; wherein the target temperature is 1450 to 1500° C.;

after the smelting process, leaving the smelted molten liquid to stand at a casting temperature of 1400 to 1420° C. for not less than 40 min, and

performing a single roller rapid quenching on the smelted molten liquid to give an iron-based amorphous alloy;

wherein the rare earth element is selected from the group consisting of La, Ce, Nd and Yb, the addition amount of the rare earth alloy is 0.005 to 0.025 wt % so that concentration of the rare earth elements in the obtained iron-based amorphous alloy is 10 ppm to 30 ppm;

wherein a, b and c respectively represent an atomic percent of corresponding components; 83.2≤a≤86.8, 11.0<b<15.0, 2.0≤c≤4.0, and a+b+c=100;

wherein saturation magnetic induction density of the iron-based amorphous alloy is ≥1.63 T;

wherein the method further comprises after the single roller rapid quenching, subjecting the iron-based amorphous alloy to a heat treatment;

wherein temperature of the heat treatment is 300 to 380° C., and time of the heat treatment is 30 to 150 min;

wherein under a condition of 50 Hz and 1.30 T, the iron-based amorphous alloy has an iron core loss of less than 0.16 W/kg; and under a condition of 50 Hz and 1.40 T, the iron-based amorphous alloy has an iron core loss of less than 0.20 W/kg.

2. The method according to claim 1 , wherein the iron-based amorphous alloy is in a completely amorphous state, having a critical state of at least 30 μm, and a width of 100 mm to 300 mm.