Effect of Sintering Conditions on the Properties of Lean PM Steels Produced through the Masteralloy Route
Obtaining robust sintering processes for steels containing oxygen-sensitive alloying elements(such as Cr,Mn and Si),requires a deep understanding of the chemical aspects of sintering.In particular the chemical reactions occurring during the heating stage will have a strong impact on the final properties.This work presents an overview on the chemical processes that need to be considered when sintering steels containing Fe-Mn-Si-(Cr)-(C)masteralloy powders,emphasizing in particular how the sintering parameters could be “adjusted to overcome the possible risks.Different heating rates and in particular combinations of inert(N2)and reducing(H2)gases during the heating stage were studied on samples sintered in a laboratory furnace and complemented with thermoanalytical studies based on dilatometry runs with a coupled mass spectrometer.The results show how the use of H2 can be risky at certain temperature ranges,as it leads to homogeneous decarburization through the formation of methane.However,with certain combinations of heating rates and atmospheres,the effect of H2 in the reduction of oxides can be very advantageously used to enhance the final properties of the sintered steel.Apart from the atmosphere and the heating rate,a major parameter that shows a strong influence on the properties is the high sintering temperature(1250℃ vs.1120℃): not only due to the higher densities achieved,but also because of the enhanced reduction of oxides.
Chemical reactions Sintering atmospheres Oxygen-sensitive elements Masteralloys Low alloy steels Internal gettering Methane formation
De Oro Calderon Raque Jaliliziyaeian Maryam Gierl-Mayer Christian Danninger Herbert
Institut für Chemische Technologien und Analytik,Technische Universit(a)t Wien,A-1060 Wien/Vienna,Austria
国际会议
北京
英文
473-480
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）