分析在高速钢通过沉淀行为.pdfVIP

Materials Science and Engineering A 398 (2005) 323–331 Analysis of the precipitation behaviour in a high-speed steel by means of small-angle neutron scattering H. Leitner a,∗, P. Staronb , H. Clemens a , S. Marsoner c , P. Warbichler d a Department of Physical Metallurgy and Materials Testing, Montanuniversit¨at Leoben, A-87 Leoben, Austria b Institute for Materials Research, GKSS Research Center, D-21502 Geesthacht, Germany c Materials Center Leoben, A-87 Leoben, Austria d Research Institute for Electron Microscopy, Center for Electron Microscopy, A-801 0Graz, Austria Received 4 August 2004; received in revised form 16 March 2005; accepted 22 March 2005 Abstract Small-angle neutron scattering (SANS) and energy-filtered transmission electron microscopy (EFTEM) were employed to characterise the precipitation behaviour in the high-speed steel HS6-5-2 during tempering. With SANS the evolution of the size distribution of precipitates during isothermal tempering at 590 ◦C was investigated. The SANS results are discussed assuming that three populations of precipitates can be distinguished during tempering at 590 ◦C. The smallest population with sizes around 1 nm is supposed to be carbon-rich clusters. Intermediate-sized particles between approximately 1 and 10 nm might be either MC and/or M2 C carbides, which cannot be distinguished by SANS. In addition, the ratioA of magnetic and nuclear scattering intensity was used to gain information on the composition of the precipitates. The A -ratio is discussed assuming a substitution of iron in the precipitates by carbide forming elements with increasing tempering time. Finally, the correlation of the results obtained by SA