Effects of Alloying Elements on Microstructure, Hardness, Wear Resistance, and Surface Roughness of Centrifugally Cast High-Speed Steel Rolls

Abstract

A study was made of the effects of carbon, tungsten, molybdenum, and vanadium on the wear resistance and surface roughness of five high-speed steel (HSS) rolls manufactured by the centrifugal casting method. High-temperature wear tests were conducted on these rolls to experimentally simulate the wear process during hot rolling. The HSS rolls contained a large amount (up to 25 vol pct) of carbides, such as MC, M 2 C, and M 7 C 3 carbides formed in the tempered martensite matrix. The matrix consisted mainly of tempered lath martensite when the carbon content in the matrix was small, and contained a considerable amount of tempered plate martensite when the carbon content increased. The high-temperature wear test results indicated that the wear resistance and surface roughness of the rolls were enhanced when the amount of hard MC carbides formed inside solidification cells increased and their distribution was homogeneous. The best wear resistance and surface roughness were obtained from a roll in which a large amount of MC carbides were homogeneously distributed in the tempered lath martensite matrix. The appropriate contents of the carbon equivalent, tungsten equivalent, and vanadium were 2.0 to 2.3, 9 to 10, and 5 to 6 pct, respectively.

Micro and Macro Hardness Correlation for High Speed Steel HSS With Mc and M2c Carbide Precipitation, Used to Produce Lamination Rolls

“…It is interesting to compare the analysis of the total carbides with the results of Dae Jin Ha [5], where it confirms that the presence of MC carbides influences the hardness of its studied alloy, which has 25% in MICRO AND MACRO HARDNESS CORRELATION … 29 the total of the different carbides, in our case the minimum values of the total of carbides were 11.74% with hardness of 58.00 HRC and the maximum was 13.16% with hardness of 59.85 HRC, confirming the theory that the higher percentage of carbides trend of increase of hardness is possible; however, Kim et al [6] carried out his study with five different alloys in an interval of 12.0 to 17.8% of carbides, and confirms that carbides with high hardness affect the toughness and fracture resistance of HSS steels, therefore it recommends to control the refinement and percentage of carbides, and suggests to use alloying elements to improve the characteristics of the matrix.…”

“…Studies on HSS materials used for the steel forming process through rolling, establishing that alloying elements such as coal, tungsten, molybdenum and vanadium generate about 25% MC, C, M 2 and 3 7 C M carbides, significantly influencing the microstructure, hardness and wear resistance of HSS steels (Dae Jin Ha [5]; Kim et al [6,7]; De Colnet [8]). …”

Effect of Nitrogen on the Microstructure and Hardness of High-Carbon High-Speed Tool Steel Type Alloys

“…Furthermore, nanosize carbides containing V or Mo precipitated on the left side of the V and Mo mapping images. Secondary carbides containing V, W, Mo or Ta are utilized for secondary hardening at high tempering temperatures [11][12][13][14][15] . Although we could not clarify the composition of the V-or Mo-containing carbides under these experimental conditions, these phases may be general secondary carbides.…”

“…HCHSSs have similar chemical compositions to high-speed steel and include hard eutectic MC-and M 2 Ctype carbides (M is a carbide-generating element such as Cr, Mo, or V) between primary austenite dendrites [5][6][7][8][9][10] . Furthermore, austenite dendrites transform to hard martensite, in which ne secondary carbides precipitate after quenching and tempering, and exhibit superior hardening [11][12][13][14][15] . To improve the wear resistance of HCHSSs, it is necessary to control the species, volume fraction, and distribution of carbides crystallized in the solidi cation process and to optimize the heat treatment conditions [16][17][18][19][20] .…”

A study of casting high‐boron high‐speed steel roll materials

“…Improving the performance of the roll to accommodate the needs of the mill is the new task that roll developers are facing. In recent years, domestic and foreign researchers have conducted lots of research about roll material . They have made breakthrough that used high speed steel to manufacture new generation compounded roll.…”