Mechanical properties and structure of castings at different ladle processing of liquid and crystalizing steel

The paper presents studies on the effect of external influences when pouring-in high-strength alloyed steel into thin-walled metalshell molds with external cooling and into the same molds with suspension pouring-in (complex effect on hardened casting). Prerequisites for the selection of these technologies are considered. As control metal, we have investigated the casting received in volume liquid glass form. Macrostructure, cross-sectional view and mechanical properties of the metal at normal (+20 °C) and raised (+350 °C) temperatures were studied. The most dense and uniform structure and cross-sectional view were received in casting at complex influence. It was established that the main advantage of the offered technologies is increase in uniformity of mechanical properties on the section and height of castings, especially of plastic properties and impact strength. The anisotropy of properties on the section and height of pilot castings is much less, than in control casting. As a result of the studies, it was found that the external and complex effect on the forming casting allows one to affect the macrostructure and to improve the mechanical properties of castings at various test temperatures of the samples. In castings obtained in a metal-shell form with forced cooling, there is no noticeable difference in the mechanical properties both in height and in cross section of the casting. Moreover, the strength properties are by an average 100 MPa higher than that of the control casting, while maintaining high values of ductility and toughness.