Bulk-solidifying high manganese non-ferromagnetic amorphous steel alloys and related method of using and making the same

An Fe-based non-ferromagnetic amorphous steel alloy comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe, Ni)a(Mn, Cr, Mo, Zr, Nb)b(B, Si, C)c
• wherein, 43≧a≧50, 28≧b≧36, 18≧c≧25, and the sum of a, b, and c is 100 and under the following constraints that Fe content is at least about 40%, Mn content is at least about 13%, Zr content is at least about 3%, and B content is at least about 12% in the overall alloy composition.

An Fe-based amorphous steel alloy, having a critical cooling rate of less than about 1,000° C./sec, and comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe, Ni)a(Mn, Cr, Mo, Zr, Nb)b(B, Si, C)c
• wherein, 43≧a≧50, 282b≧36, 18≧c≧25, and the sum of a, b, and c is 100 and under the following constraints that Fe content is at least about 40%, Mn content is at least about 13%, Zr content is at least about 3%, and B content is at least about 12% in the overall alloy composition.

An article of Fe-based amorphous steel alloy, having minimum dimension of at least about 0.1 mm, and comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe, Ni)a(Mn, Cr, Mo, Zr, Nb)b(B, Si, C)c
• wherein, 43≧a≧50, 28≧b≧36, 18≧c≧25, and the sum of a, b, and c is 100 and under the following constraints that Fe content is at least about 40%, Mn content is at least about 13%, Zr content is at least about 3%, and B content is at least about 12% in the overall alloy composition.

An Fe-based amorphous steel alloy, having a critical cooling rate of less than about 1,000°C./sec, and comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe)a (Mn, Cr, Mo)b (B, C)c
• wherein 45≧a≧55, 23≧b≧33, 18≧c≧24, and the sum of a, b, and c is 100 and under the following constraints that Mo content is at least about 12%, Mn content is at least about 7%, Cr content is at least about 3%, C content is at least about 13%, and B content is at least about 4% in the overall alloy composition.

An Fe-based non-ferromagnetic amorphous steel alloy comprised substantially of a composition having the formula:

• Fe100-a-b-c-d-e-fMnaMobCrcBdPeCf
• wherein a, b, c, d, e, and f respectively satisfy the relations:
• 15≧a≧5, 14≧b≧8, 10 ≧c ≧4, 8≧d≧0, 12≧e≧5, 16≧f≧4, these subscript values indicating the atomic percent amounts of the constituent elements of the composition.

An Fe-based non-ferromagnetic amorphous steel alloy comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe)a(Mn, Cr, Mo)b(B, P, C)c
• wherein, 47≧a≧59, 20≧b≧32, 19≧c≧23, and the sum of a, b, and c is 100 and under the following constraints that Mo content is at least about 7%, Mn content is at least about 4%, Cr content is 3%, C content is at least about 3%, P content is at least about 4%, and B content is at least about 4% in the overall alloy composition.

An Fe-based amorphous steel alloy, having a critical cooling rate of less than about 1,000° C./sec, and comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe)a(Mn, Cr, Mo)b(B, P, C)c
• wherein, 47≧a≧59, 20≧b≧32, 19≧c≧23, and the sum of a, b, and c is 100 and under the following constraints that Mo content is at least about 7%, Mn content is at least about 4%, Cr content is at least about 3%, C content is 3%, P content is at least about 4%, and B content is at least about 4% in the overall alloy composition.

An article of Fe-based amorphous steel alloy, having minimum dimension of at least about 0.5 mm, and comprised substantially of a composition represented by the formula (in atomic percent):

• (Fe)a(Mn, Cr, Mo)b(B, P, C)c
• wherein, 47≧a≧59, 20≧b≧32, 19≧c≧23, and the sum of a, b, and c is 100 and under the following constraints that Mo content is at least about 7%, Mn content is at least about 4%, Cr content is at least about 3%, C content is at least about 3%, P content is at least about 4%, and B content is at least about 4% in the overall alloy composition.