Abstract: A method of manufacturing iron-based powder includes providing an iron-based molten steel manufactured through a iron making process and a steelmaking process to a tundish; and performing water atomization over the molten steel discharged through a nozzle connected to the tundish. The iron-based powder is manufactured from the molten steel refined after a molten iron tapped from a iron making process is charged into a converter without a pre-treatment process of the molten iron, thus economically providing the highly clean iron-based powder.

Abstract: A method of manufacturing iron-based powder includes providing an iron-based molten steel manufactured through a iron making process and a steelmaking process to a tundish; and performing water atomization over the molten steel discharged through a nozzle connected to the tundish. The iron-based powder is manufactured from the molten steel refined after a molten iron tapped from a iron making process is charged into a converter without a pre-treatment process of the molten iron, thus economically providing the highly clean iron-based powder.

Abstract: A high speed tool steel and a manufacturing method therefor are disclosed, in which carbides are formed in the matrix in a uniform manner, thereby obtaining a high toughness and a high abrasion resistance. The high speed tool steel according to the present invention includes a basic composition of WaMobCrcCodVxCyFez where the subscripts meet in weight %: 5.0%≦a≦7.0%, 4.0%≦b≦6.0%, 3.0%≦c≦5.0%, 6.5%≦d≦9.5%, 2.2% ≦x≦8.3%, 1.1%≦y≦2.18%, and 66.52%≦z≦73.7%. The final structure has carbides uniformly distributed within a martensite matrix, which are mainly MC and M6C carbides. The method includes the steps of melting the above-defined alloy composition, gas spraying the melted alloy to form a bulk material, heat treating the bulk material to decompose the M2C carbides to stabilize M6C carbides and hot working the heat treated bulk material to a desired shape.

Abstract: A high speed tool steel and a manufacturing method therefor are disclosed, in which carbides are formed in the matrix in a uniform manner, thereby obtaining a high toughness and a high abrasion resistance. The high speed tool steel according to the present invention includes a basic composition of W.sub.a Mo.sub.b Cr.sub.c Co.sub.d V.sub.x C.sub.y Fe.sub.z where the subscripts meet in weight %: 5.0%.ltoreq.a.ltoreq.7.0%, 4.0%.ltoreq.b.ltoreq.6.0%, 3.0%.ltoreq.c.ltoreq.5.0%, 6.5%.ltoreq.d.ltoreq.9.5%, 2.2%.ltoreq.x.ltoreq.8.3%, 1.1%.ltoreq.y.ltoreq.2.18%, and 66.52%.ltoreq.z.ltoreq.73.7%. The final structure has carbides uniformly distributed within a martensite matrix, which are mainly MC and M.sub.6 C carbides. The method includes the steps of melting the above-defined alloy composition, gas spraying the melted alloy to form a bulk material, heat treating the bulk material to decompose the M.sub.2 C carbides to stabilize M.sub.6 C carbides and hot working the heat treated bulk material to a desired shape.