RT Journal Article
T1 New Alloying Systems for Sintered Steels: Critical Aspects of Sintering Behavior
A1 Oro, Raquel
A1 Campos Gómez, Mónica
A1 Gierl-Mayer, Christian
A1 Danninger, Herbert
A1 Torralba Castelló, José Manuel
AB Oxygen-sensitive alloying elements such as Mn, Si, and Cr have a high  potential for improving the properties of low alloyed sintered steels  while reducing the alloying cost. However, it is necessary to find a way  for avoiding, or at least minimizing, the oxidation of these elements  especially during the early stages of the sintering cycle. In this study  Mn, Si, and Cr were introduced in the form of a master alloy powder  designed to be mixed with the iron base powder and provide the final  composition of the steel during the sintering process. The  reduction/oxidation phenomena taking place during the heating stage were  studied by thermogravimetry, dilatometry, and mass spectroscopy, using  either reducing (H2) or inert (Ar)  atmospheres. The results show how the difference in chemical activity  between base iron powder and master alloy causes the so called  "internal-getter" effect, by which the reduction of less stable iron  oxides leads to oxidation of the elements with higher affinity for  oxygen. This effect can be somehow minimized when sintering in H2,  since the iron oxides are reduced at lower temperatures at which the  reactivity of the elements in the master alloy is lower. However, H2  concentration in the processing atmosphere needs to be carefully  adapted to the specific composition of the materials being processed in  order to minimize decarburization by methane formation during sintering.
PB Springer
SN 1073-5623 (print)
SN 1543-1940 (online)
YR 2015
FD 2015-03
LK https://hdl.handle.net/10016/19930
UL https://hdl.handle.net/10016/19930
LA eng
NO Höganäs AB Sweden, financial support provided through the Höganäs Chair IV
DS e-Archivo
RD 27 jul. 2024