Abstract
To identify the design parameters in heat treatments that have a significant effect on the erosive wear resistance of hypoeutectic high chromium white cast irons, a design of experiment was applied to a white cast iron with 18wt.% Cr and 2wt.% Mo. The analyzed factors were the destabilization heat treatment of austenite (1000 or 1100 °C, for 4 or 8 h), different quench cooling media (in air or oil), different tempering treatments (200 or 500 °C, for 3 or 6 h), and the application of an ionic nitriding treatment. Despite what was expected, the nitriding treatment was not found to have a significant effect on said wear resistance. However, it is concluded that the highest wear resistance is obtained with the shortest dwell time at the destabilization temperature (4 h), quenching in oil, and with the shortest tempering times (3 h). Among the nitrided samples, the highest nitrided layer thicknesses were obtained when the destabilization temperature of the austenite was 1000 °C and the tempering temperature was 200 °C.
Highlights
White cast irons with a percentage of Cr greater than 15wt.% show two microstructural peculiarities that condition their properties
To identify the design parameters in heat treatments that have a significant effect on the erosive wear resistance of hypoeutectic high chromium white cast irons, a design of experiment was applied to a white cast iron with 18wt.% Cr and 2wt.% Mo
It is concluded that the highest wear resistance is obtained with the shortest dwell time at the destabilization temperature (4 h), quenching in oil, and with the shortest tempering times (3 h)
Summary
White cast irons with a percentage of Cr greater than 15wt.% show two microstructural peculiarities that condition their properties. The content of M7 C3 type eutectic carbides increases gradually with the increase in chromium content [3] These carbides have a similar morphology to bars or plates [4]. Martensite may form at relatively low cooling rates due to the high hardenability conferred by a high alloy content in solid solution of austenite prior to quenching. One such alloying element is chromium, which allows martensite to form by air cooling [1]. Wear resistance is improved if the precipitation of chromium-rich secondary carbides [6,7], uniformly distributed in a predominantly martensitic matrix, is promoted and if the Metals 2019, 9, 403; doi:10.3390/met9040403 www.mdpi.com/journal/metals
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
