| 摘要 |
<p>A high speed tool steel produced by sintering powder, consisting essentially, by weight, of more than 1.5% but not more than 2.2% C, not more than 1.0% Si, not more than 0.6% Mn, 3.0 to 6.0% Cr, W and/or Mo in which the content of W + 2Mo is in the range of 20 to 30% and in which the ratio of W/2Mo is not less than 1, not more than 5.0% V, 2.0 to 7.0% Nb, the ratio of Nb/V being not less than 0.5, and the balance Fe and incidental impurities, the value of C-Ceq, which Ceq is defined by 0.24 + 0.033 X W + 0.063 X Mo + 0.2 X V + 0.1 X Nb, being in a range of -0.20 to 0.05, the density of carbides having grain size of 2 to 5 mu m being in a range of 10,000 to 30,000 pieces/mm<2>.</p> |
