摘要 |
Tool steel is made by powder metallurgy using a pre-alloyed powder of high purity contg. (in wt.%): < 1 Mn, < 1.5 Si, 6.05-6.45 Cr, 2.5-3.5 Mo, 1.5-2.4 Nb, 6-8.5 V, max. 0.02S, max. 0.03P, max 100 ppm. O, 2-2.8 C, and balance Fe plus usual impurities. The steel has a dispersion of carbide of type MC of Nb and V in an amt. of approx. 15%. The pref. compsn. is 0.3-0.5 Mn, 0.3-0.9 Si, 6.05-6.45 Cr, 2.75-3.25 Mo, 1.6-2 Nb, 7.75-8.25 V, max. 0.01S, max. 0.02P, max. 100 ppm. O, 2.38-2.45 C. |