| A study was made of the effects of alloying elements on microstructural factors and wear properties of four high speed steel (HSS) rolls manufactured by centrifugal casting method. A simulation test was carried out using a high-temperature wear tester capable of controlling speed, load, and temperature. The test results revealed that the HSS roll containing a larger amount of vanadium showed the best wear resistance because it contained a number of hard MC carbides. However, it showed a very rough roll surface because of the cracking along cell boundaries, the preferential removal of the matrix, and the sticking of the rolled material to the roll during the wear process, thereby leading to increase in friction coefficient and rolling force. In order to improve wear resistance with consideration of the roll surface roughness, it is suggested that reduction in the vanadium content, solid solution hardening by adding alloying elements, secondary hardening by precipitation of fine carbides in the matrix, and formation of fine prior austenite grain boundaries by pre-austenitization treatment are required to strengthen the matrix which can hold hard carbides in it. |
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