Influence of Casting Technology on the Properties of Cast Steel Billet

Resumo

Abstract—The influence of the solidification of high-strength moderately alloyed steel on the mechanical properties of the castings is studied experimentally. The low-temperature strength is of particular interest, since it determines the reliability and performance of cast products. The impact strength, work of crack development, and fiber content in the fractures are plotted as a function of the test temperature. Three production technologies for castings are considered: (1) casting in a thin-walled mold with forced water–air cooling that varies over the ceramic-layer height (casting with external cooling); (2) casting in the same conditions with the introduction of solid microcooling particles in the liquid steel (casting with complex cooling); (3) casting in a sand (liquid-glass) mold (the control technology). The results indicate that the impact strength is higher in the first two cases, over the whole temperature range. The variation in impact strength is smoother in those two cases; and the sharp decrease in impact strength seen in the control samples is not evident. The work of crack development W_cd also depends on the casting conditions. Serial curves show that the steel cast in the first two cases is less inclined to brittle failure (greater cold strength). Analogous results are obtained in studying the fiber content of the fractures.