Berchuk D. Laws of late modifying and cooling speed influence on structure of high-strength cast iron castings

The laws allowed to estimate the influence degree of such chemically active modifying elements as Ba, Ca, Mg, Sr, Zr, REM in composition of FeSi rich alloy on formation of phase composition and structure of high-strength cast iron castings are systematically researched and established. Are defined parameters of late modifying processes, which in a combination with cooling speed (8,5-10,5 °C/c) in the characteristic castings wall thickness 2,5…3 mm, provide reception of crushed cast structure consisting of spheroidal graphite pluggings in diameter less than 9 microns with density of distribution more than 1100 mm-2 and metal basis from fine-grained ferrite (7…9 point) and platy pearlite (Pd 0,3) that promotes quality improving and increasing of mechanical properties of thin-walled castings. Kinetic features of magnesium rich alloys dissolution in liquid cast iron are experimentally established at in-mould modifying depending of pouring temperature. The quantitative correlation of Mg, Si, Ni contents with structure and mechanical properties of high-strength cast iron are established.