| 摘要 |
PURPOSE:To obtain the titled steel having hardness and wear resistance approximated to that of sintered ultrahard alloy, by adding one kind or more of carbide and nitride having smaller than a prescribed average particle diameter to tool steel atomized powder having smaller than a prescribed average particle diameter, compacting and sintering them. CONSTITUTION:A tool steel atomized powder of <=350 mesh and <=25mum average particle diameter being water atomized or gas atomized fines, one kind or more of carbide and nitride powders of <=5mum average particle diameter is added by 1.0-50wt%. The obtd. mixed powder is compacted and sintered by normal method, but typically compacted and sintered by CIP compacting at 5,000(ata), and vacuum sintering at 1,200 deg.C-2hr respectively. Next, the obtd. sintered steel is HIP treated, then annealed and machined to obtain tool material of >=99% density ratio. As the carbide and the nitride, carbide of Ti, V, Zr, etc., and nitride similarly of Ti, V, Zr, etc., can be exemplified respectively.
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