All alloying techniques for high strength applications rely on retarding the ferrite-pearlite and the bainite transformation during cooling from the sintering heat in order to form fully or partially martensitic microstructures. In the present paper it was investigated whether a kerosene atomised master alloy on pure iron base containing 10 % Cr and Mn is able to fulfill the technological requirements in high performance powder metallurgical steels. It is the aim to obtain a yield strength level of 550 N/mm2 at a minimum of alloying cost. The results reveal that Cr-Mn-alloying necessitates high temperature sintering and is possible without excessive tool wear or infringement of patents via kerosene atomised master alloys. The strength levels which can be obtained at slow cooling rates can serve applications with high service stresses, e. g. in passenger car gear boxes. The total amount of alloying elements for a required strength level is far lower than in traditional recipes. For an optimum yield strength a tempering treatment of 300 C deg or higher is recommended, 200 C deg are not sufficient to exploit the potential of the steel. With the existing master alloy a microstructural homogenisation is not possible, the steel consists mainly of bainite with martensite around the non-etching former master alloy particles.
Cr-Mn-Mo-alloyed high performance steel via kerosene atomised master alloy
2005
8 Seiten, 8 Bilder, 4 Tabellen, 12 Quellen
Aufsatz (Konferenz)
Englisch
Kawasaki Steel unveils new atomised steel powders
Tema Archiv | 1985
NTRS | 1980
|SAE Technical Papers | 1913
|Engineering Index Backfile | 1910
|SAE Technical Papers | 1913
|