Provided is a FeMnC-based twinning-induced plasticity (TWIP) steel which includes 13 wt % to 24 wt % of manganese (Mn), 0.4 wt % to 1.2 wt % of carbon (C), and iron (Fe) as well as other unavoidable impurities as a remainder, is manufactured by caliber rolling, has a microstructure including elongated grains that are elongated in a rolling direction, and has an average grain size of the elongated grains in a direction perpendicular to the rolling direction of 1 m or less.

The present invention achieves an object of continuously supplying a melt from a melt nozzle over a long period of time by adjusting the contents of Mn and S in an FeBSiC-type amorphous alloy ribbon. An amorphous alloy ribbon of the present invention includes a composition containing Fe, Si, B, C, Mn, S, and inevitable impurities, the composition containing, with respect to 100.0 atm % of the total amount of Fe, Si, B, and C, 3.0 atm % or more and 10.0 atm % or less of Si, 10.0 atm % or more and 15.0 atm % or less of B, and 0.2 atm % or more and 0.4 atm % or less of C, the amorphous alloy ribbon having a content ratio of Mn of more than 0.12 mass % and less than 0.15 mass %, and a content ratio of S of 0.0036 mass % or more and less than 0.0045 mass %, the amorphous alloy ribbon having a thickness of 10 m or more and 40 m or less, and a width of 100 mm or more and 300 mm or less.

An ultrafine-crystalline alloy ribbon having a composition represented by the general formula of Fe.sub.100-x-y-zA.sub.xB.sub.yX.sub.z, wherein A is Cu and/or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0<x5, 8y22, 0z10, and x+y+z25 by atomic %, and a structure in which ultrafine crystal grains having an average particle size of 30 nm or less being dispersed in a proportion of more than 0% and less than 30% by volume in an amorphous matrix; an ultrafine crystal grains-depleted region comprising ultrafine crystal grains at a number density of less than 500/m.sup.2 being formed in a region of 0.2 mm in width from each side of the ribbon.

A nano-pearlite rail and a process for manufacturing the same wherein the rail has excellent mechanical properties, including a tensile strength of no less than 1300 MPa, a yield strength of no less than 1000 MPa, a hardness of HRC 44-47, and an elongation of no less than 10%, as well as excellent wear resistance and fatigue resistance, and is particularly suitable for applications in heavy-haul railways, especially for the railway segments having a sharp turn, and for a wing rail in a bainite steel combined frog.

There is provided a thermoelectric conversion material made of a full-Heusler alloy and capable of enhancing figure of merit. In order to solve the above problem, the thermoelectric conversion material is made of the full-Heusler alloy represented by the following composition formula: (Fe.sub.1-xM1.sub.x).sub.2+(Ti.sub.1-yM2.sub.y).sub.1+(A.sub.1-zM3.sub.z).sub.1+. A composition in a ternary phase diagram of FeTi-A is inside a hexagon having points (50, 37, 13), (45, 30, 25), (39.5, 25, 35.5), (50, 14, 36), (54, 21, 25), and (55.5, 25, 19.5) as apexes. Further, an amount of change VEC of an average valence electron number per atom VEC in the case of x=y=z=0 satisfies a relation 0<|VEC|0.2 or 0.2<|VEC|0.3.

A metal strip is provided having a casting-wheel side that has been solidified on an outer surface of a heat sink, an opposing, air side and a microstructure. The microstructure is at least 80 vol. % amorphous or has at least 80 vol. % nanocrystalline grains and a residual amorphous matrix in which at least 80% of the nanocrystalline grains have an average grain size of less than 50 nm and a random orientation. The air side of the metal strip has a surface crystallisation proportion of less than 23%.

Surface-treated steel including a steel sheet; a plated layer including zinc formed on the steel sheet; and a film formed on the plated layer, the film having a thickness of 100 nm or more and 1000 nm or less, and including an amorphous phase A containing Si, C, O, P, Zn, and V, and one or more selected from the group consisting of Ti, Zr, and Al as constituent elements, with a Zn/Si ratio of peak intensity between Zn and Si, is 1.0 or more, and a mass ratio between V and P, V/P is 0.050 to 1.000 when analyzed by EDS; and an amorphous phase B containing Si, O, and Zn, having a Zn/Si ratio of less than 1.0, and Zn content of the amorphous phase A is 10 mass % or less, when analyzed by EDS.

Manufacturing a cold-rolled steel plate by smelting a steel slab having the chemical composition containing on the basis of percent by mass, C from 0.03 to 0.12%, Si from 0 to 1.0%, Mn from 0.2 to 0.8%, P at 0.03% or less, S at 0.03% or less, Ti from 0.04 to 0.3%, and Al at 0.05% or less, with a residue being formed of Fe and unavoidable impurities, the chemical composition satisfying 5*C %Si %+Mn %1.5 *Al %<1, and an average diameter of particles of a Ti-based carbide as a precipitate is from 20 to 100 nm; heating the slab to 1200 C. or more and hot rolling, forming a hot-rolled steel plate; winding the hot-rolled steel plate from 500 to 700 C. to form a hot-rolled coil; and cold rolling or annealing and cold rolling the coil obtaining cross-sectional hardness from 200 to 400 HV.

A filament according to an aspect of the present invention includes a predetermined chemical composition, in which a diameter r of the filament is 0.15 mm to 0.35 mm, a soft portion is formed along an outer circumference of the filament, the Vickers hardness of the soft portion is lower than that of a position of the filament at a depth of of the diameter r by Hv 50 or higher, the thickness of the soft portion is 1 m to 0.1r mm, the metallographic structure of a center portion of the filament contains 95% to 100% of pearlite by area %, the average lamellar spacing of pearlite in a portion from a surface of the filament to a depth of 1 m is less than that of pearlite at the center of the filament, the difference between the average lamellar spacing of pearlite in the portion from the surface of the filament to the depth of 1 m and the average lamellar spacing of pearlite at the center of the filament is 2.0 nm or less, and the tensile strength is 3200 MPa or higher.

A method for forming an austempered iron composition with a nanoscale microstructure includes a step of heating an iron-carbon-silicon alloy with silicon to a first temperature that is lower than A1 for the iron-carbon-silicon alloy. The iron-carbon-silicon alloy is then adiabatically deformed such that the temperature of the iron-carbon-silicon alloy rises to a second temperature which is sufficient to form proeutectoid ferrite and austenite. The iron-carbon-silicon alloy is cooled to a first austempering temperature. The iron-carbon-silicon alloy is then heated to a second austempering temperature that is greater than the first austempering temperature to form a dual phase microstructure. Characteristically, the dual phase microstructure includes proeutectoid ferrite and ausferrite.