J. Phys. IV France 03 (1993) C8-307-C8-310
X-ray diffraction study of precipitation in melt-spun high speed steelsJ. HÄRLE, P. LAMPARTER and S. STEEB
Max-Planck-Institut für Metallforschung, Institut für Werkstoffwissenschaft, Seestrasse 92, 70174 Stuttgart, Germany
The high speed steels ASP30 and ASP60 were rapidly quenched from the melt using the melt spinning method. Their structure was investigated in the as-quenched state as well as in-situ during annealing at 560 °C and 700 °C, respectively. The carbide precipitates were identified by wide angle X-ray diffraction. For the small angle X-ray scattering measurements (down to Qmin = 2 x 10-3 Å-1) a laboratory-built pin hole instrument, equipped with a furnace and a 2-dimensional detector, was used. Slowly growing M6C-carbides are the dominant precipitates. Rapidly growing MC-carbides are present in ASP60 with a smaller fraction, but no M2C-carbides develop. The coarsening of the precipitates saturates at long annealing times. The Johnson-Mehl-Avrami analysis of the evolution of the volume fraction of M6C in ASP60 indicates a transition in the precipitation kinetics.
© EDP Sciences 1993