Powder Metallurgy Manufacturing of Carbon-Free Precipitation Hardened High Speed Steels
H. Danninger a, Ch. Harold a, Ch. Gierl a, H. Ponemayr b, M. Daxelmueller c, F. Simancik d and K. Izdinsky d
a Vienna University of Technology, A-1060 Wien, Austria
b Boehler-Ybbstal Profil GmbH, A-3333 Boehlerwerk, Austria
c Boehler Uddeholm Precision Strip GmbH, A-3333 Boehlerwerk, Austria
d Institute of Materials and Machine Mechanics SAS, SK-83102 Bratislava, Slovakia
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Carbon-free steels of the type Fe-Co-(Mo,W) have been known for long to attain very high hardness levels through precipitation hardening. However, the classical ingot metallurgy route tended to result in brittle materials. Here it is shown that the powder metallurgy route through mixing of elemental powders, pressing and sintering results in materials with excellent combination of hardness and transverse rupture strength if the processing parameters are adjusted accordingly, in particular sintering and heat treatment being critical stages that should result in chemically homogeneous and fine-grained microstructure. If properly processed, these steel grades offer excellent red hardness since the hardening intermetallic phases are much less sensitive to overaging than the secondary carbides in standard high speed steels.
DOI: 10.12693/APhysPolA.117.825
PACS numbers: 81.05.Bx, 81.40.-z