FABRICATION OF STD11 CAST STEEL BLADE CONTAINING ADDED CARBIDE-FORMING ELEMENT TI

The study was intended to develop a STD11 cast steel blade with improved mechanical properties instead of the STD11 rolled material that was used as a wheel blade material of a shot blasting machine by precision casting, with the aim of enabling the industry to manufacture new high-strength high-wear resistant alloy tool steel cast steel blade with improved life expectancy despite of strong impact wear, thus realizing economical technology development. The control the size and distribution of coarse eutectic carbides, which are known to be the main cause of strength reduction in cast steels, by adding a small amount of Ti, and the reduction of Cr carbides by the formation of fine TiC carbides to improve mechanical properties were targeted as the core technology of this study. In other words, about 1.5 to 2.0 wt.% of Ti, which is known to have a high effect as a strong carbide-forming, was added to the basic chemical composition of STD11 steel to form TiC carbide, the blade was fabricated by precision casting with an alloy composition with increased carbon from 1.5wt.% to 1.8wt.% to improve the quenching hardenability, and then quenched at 1030℃ and tempered at 170℃ at low temperature to improve hardness and wear resistance.