Comparative Analysis of Mechanical Properties and Cold Resistance of Metal of Steel Castings from the Special Alloyed Steel

In this paper, the experimental observation of influence of casting conditions on steel alloy quality is presented. We studied the casted steel samples obtained with the following methods: sand casting mold (as a reference sample), thin-wall mold with height-adjusted ceramic layer and forced water-air mixture cooling, same as above but with micro-cooling channels used during liquid steel casting. We showed that the steel density as well as typical distribution of non-metallic inclusions and mechanical properties are dependent on casting technology been used. We present the figures of impact toughness, crack growth energy and filamentation ratio with respect to the test temperature. We observed that the impact toughness of the samples is higher than for the reference one within the entire test temperature range. In particular, the impact toughness exhibits a smooth dependence versus temperature as opposed to its abrupt decrease for a reference sample. We showed, that the samples obtained according to the new technology are less fragile and have better cold resistance, similar results were obtained after crack filamentation ratio analysis. (paper)