Super hard high-speed tool steel
AssigneeHitachi Metals, Ltd.
InventorNorimasa Uchida
Life of this patent
Estimating the term…
Abstract
A super hard high-speed tool steel having a composition satisfying the condition of 0.ltoreq.C-Ceq.ltoreq.0.6 (where Ceq=0.06Cr+0.033 W+0.063 Mo+0.2 V within the range of 1.7.ltoreq.C.ltoreq.4.1%, the composition containing 3 to 10% of Cr, 1 to 20% of W, 1 to 15% of Mo (where 18.ltoreq.W+2Mo.ltoreq.40), 1 to 15% of V, not greater than 15% of Co, not greater than 2% of Si, not greater than 1% of Mn, and the balance substantially Fe and inevitable impurities, the steel further containing in uniformly dispersed state 2 to 12% in total of one, two or more selected from a group consisting of nitrides, carbides and carbonitrides of Ti, V, Zr, Nb, Hf and Ta in the composition. This tool steel exhibits a distinguished hardness of HRC 71 or higher, as well as toughness.
Claims7
A high-speed tool steel capable of high hardness and toughness, formed by preparing an atomized matrix powder of a high-speed tool steel having a composition which satisfies the condition of 0.ltoreq.C-Ceq.ltoreq.0.6 (where Ceq=0.06 Cr+0.033 W+0.063 Mo+0.2 V) within the range of 1.7.ltoreq.C.ltoreq.4.1%, said composition containing 3 to 10% Cr, 1 to 20% W, 1 to 15% Mo (where 18 .ltoreq.W+2 Mo.ltoreq.40) 1 to 15% V, not greater than 15% Co, not greater than 2% Si, not greater than 1% Mn, and the balance of said matrix being substantially Fe and inevitable impurities;
- uniformly mixing 88 to 98% of said matrix powder and 2 to 12%, based upon the total, of a powder of one or more hard substances selected from the group consisting of nitrides, carbides and carbonitrides mixture.
A high-speed tool steel having high hardness and toughness according to claim 14, wherein said steel exhibits a hardness not lower than HRC 72 after a hardening-and-tempering treatment.
Dependencies are inferred from the claim text.