Development of machinability enhanced tool steels for improved product economy in hard milling
The primary objective of this project is to present a scientific approach for the development of the next generation of hot-working and cold-working tool steels. Towards this, reference hot- (type H13) and cold-working (type D2) steels were modified through alloying, inclusion and structure control as well as P/M processing. Mapping of the macro and microstructure of the steels including carbide and inclusion content as well as all mechanical and application related properties was carried out. Machinability behaviour of the steels was investigated using two sets of studies, mostly using coated cemented carbide tools. The laboratory hard-milling studies were aimed at generating fundamental information relating microstructure of the steels to chip formation, cutting forces and tool-wear mechanisms. Full-scale hard-milling tests including cavity milling were used to generate tool-life data along with the economic machinability domain using the tool-material pair (TMP) approach. The results indicate that machinability limitations in hard-milling are tool and cutting condition specific. Intrinsic improvement in machinability in hard-finish milling clearly demands superior structure control. Even with the state-of-the-art tools used, traditional machinability improving additives are not always adequate and fine primary carbide distribution appears to be critical. This was especially so in the case of limiting cutting conditions of hard-milling. However, some of the steels exhibited a broader operation domain that facilitates product flexibility in practice. Proposed strategies to improve the machinability of hardened tools steels in economic terms clearly indicates that the original project objectives have been successfully achieved.
Bibliographic Reference: EUR 21726 EN (2005), 233 pp. Euro: 35
Availability: Katalogue Number: KI-NA-21726-EN-S The paper version can be ordered online and the PDF version downloaded at: http://bookshop.eu/
ISBN: ISBN: 92-894-9872-2
Record Number: 200518388 / Last updated on: 2005-10-05
Original language: en
Available languages: en