A rapidly quenched Fe-based soft-magnetic alloy ribbon having wave-like undulations on a free surface, the wave-like undulations having transverse troughs arranged at substantially constant intervals in a longitudinal direction, and the troughs having an average amplitude D of 20 mm or less, is produced by a method comprising (a) keeping a transverse temperature distribution in a melt nozzle within 15 C. to have as small a temperature distribution as possible in a melt paddle of the alloy, and (b) forming numerous fine linear scratches on a cooling roll surface by a wire brush, thereby providing a ground surface of the cooling roll with an arithmetical mean (average) roughness Ra of 0.1-1 m and a maximum roughness depth Rmax of 0.5-10 m.

A continuous casting apparatus and method is disclosed for casting a metal strip with a cross sectional form which varies along the length of the strip. The apparatus comprises: opposing cooling means; a molten metal feed system positionable to provide a molten metal feed for solidification between the opposing cooling means to form a solidified metal strip along a length direction; and a form adjustment system. The form adjustment system comprises at least one dam to determine, at least in part, the cross sectional form of the molten metal feed to the opposing cooling means. In this way, it is possible to determine the cross sectional form of the solidified metal strip. The dam is moveable during operation of the apparatus to vary the cross sectional form of the molten metal feed to the opposing cooling means. The apparatus further comprises a molten metal pressure control system, operable to control the pressure of the molten metal in the molten metal feed during operation of the apparatus in coordination with movement of the dam. Optionally, the dam acts as a diverter, operational to divert the flow of molten metal to form an opening in the cast strip.

The invention provides a method of producing an amorphous alloy ribbon, the method including a step of producing an amorphous alloy ribbon by discharging a molten alloy through a rectangular opening of a molten metal nozzle having a molten metal flow channel along which the molten alloy flows, the opening being an end of the molten metal flow channel, onto a surface of a rotating chill roll, in which, among wall surfaces of the molten metal flow channel, a maximum height Rz(t) of a surface t, which is a wall surface parallel to a flow direction of the molten alloy and to a short side direction of the opening, is 10.5 m or less.

The invention provides a method of producing an amorphous alloy ribbon, the method including a step of producing an amorphous alloy ribbon by discharging a molten alloy through a rectangular opening of a molten metal nozzle having a molten metal flow channel along which the molten alloy flows, the opening being an end of the molten metal flow channel, onto a surface of a rotating chill roll, in which, among wall surfaces of the molten metal flow channel, a maximum height Rz(t) of a surface t, which is a wall surface parallel to a flow direction of the molten alloy and to a short side direction of the opening, is 10.5 m or less.

A cooling roll includes flow channels piercing a side surface of the cooling roll in a rotation-axis direction. The flow channels are arranged at uniform spacing on two or more concentric circles having a rotation axis of the roll as a center. A manufacturing apparatus of an amorphous alloy strip includes the cooling roll. Thereby, the amorphous alloy strip having a large thickness can be manufactured in industrial scale.

The mould contains a casting wheel, on the outer surface of which an open channel is made, a continuous tape adjacent to the casting wheel from its outer surface in such a way as to close the specified open channel, as well as a cooling system able of adjustable supply of coolant to the casting wheel and the continuous tape at least on the outer surface, on the inner surface and on both side surfaces of the wheel, in which the ratio of the coolant flow on the inner surface of the wheel to the coolant flow on the outer surface of the wheel is 1.9-3.0, and the ratio of the total coolant flow on the side surfaces of the casting wheel to the coolant flow on the inner surface of the casting wheel is 1.3-1.7.