Abstract: A steel powder suited for powder metallurgical purposes consists of an amorphous to compact-grained, essentially dendrite-free material with irregularly cornered particle shape. Such a steel powder may be produced by causing molten steel to form at least one discrete, relatively thin film on a relatively cold metal surface of great cooling capacity, causing the thin film to solidify extremely rapidly on the metal surface to form a brittle amorphous to compact-grained, in principle completely dendrite-free steel film, and crushing or grinding the brittle film into a powder of an irregularly cornered particle shape.

Abstract: A steel flake product, suitable for being crushed or ground to form a steel powder for powder metallurgical purposes, consists of a plurality of relatively thin, brittle and easily crushed, substantially dendrite-free steel flakes of amorphous to compact-grained structure. Such steel flakes are produced by causing molten steel to form at least one discrete, relatively thin flake-shaped layer on a relatively cold metal surface of great cooling capacity, moving rapidly and substantially across the direction of delivery of the molten steel. Due to the great cooling capacity the layer is made to solidify extremely rapidly.

Abstract: An improved reinforcing material for concrete and comprising a multitude of relatively short and substantially straight steel flakes. The steel flakes are of a shape tapering towards the ends of the flakes, and they have a thickness of about 0.1 mm to about 0.5 mm, a maximum width of at least about ten times the thickness, but at least about 2 mm, and a length of at least about 100 times the thickness. They are intended to be uniformly distributed and in principle randomly orientated in the concrete. The most preferred dimensions are: thickness 0.1 to 0.2 mm, maximum width 4 to 6 mm, and length 20 to 80 mm.

Abstract: An improved reinforcing material for concrete is manufactured by causing molten steel to impinge upon a relatively cold metal surface of great cooling capacity, moving rapidly substantially across the direction of delivery of the molten steel, to form at least one discrete relatively thin flake-shaped layer of molten steel on the metal surface, causing the layer to solidify on said metal surface to form a steel flake, and mutually adjusting the parameters which determine the shape and the dimensions of the steel flakes so as to give the flakes a shape tapering towards the ends of the flake and a thickness of about 0.1 mm to about 0.5 mm, a maximum width of at least about ten times the thickness but at least about 2 mm, and a length of at least about 100 times the thickness.