Study on Wear Resistance Property of High-Cr Cast Iron
Date Issued
2010
Date
2010
Author(s)
Wang, Sheng-Hau
Abstract
High-Cr white cast irons have been used extensively in industries with both abrasive and erosive environments, such as mining and mineral processing (hammers, crushers, ball mills, pulverized rolls, etc.) and steel rolling process (rolling rolls) which require high wear resistance property. In this study, both erosion and pin-on-disc tests were performed to evaluate the effects of chemical composition and heat treatment condition on wear resistance property of high-Cr white cast irons. Microstructure observations show that alloys in quenched state consist of eutectic M7C3 carbides, martensite, M23C6 secondary carbides and a substantial amount of retained austenite. On the other hand, alloys in quenched and tempered state consist of eutectic M7C3 carbides, tempered martensite, M23C6 secondary carbides dispersed in tempered martensite and a small amount of retained austenite (depending upon tempering temperature). Erosion test results indicate that varying chemical composition (C, Cr and Mo contents), but maintaining at similar heat treatment conditions, exerts little influence on erosion property in terms of erosion rate and depth, although the microstructures were changed somewhat. Furthermore, erosion testing on selected alloys with different tempering temperatures concludes that the erosion property correlated positively with alloy hardness, that is, the resistance to erosion decreases with increasing alloy hardness. However, reverse results were obtained in the pin-on-disc testing. This can be explained by that facts the material removal is the main cause of crack growth when erosion, but when pin-on-disk test the main cause of material removal is cutting.
Subjects
High-Cr cast iron
Heat treatment
Erosion
Type
thesis
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