MICRODISTRIBUTION OF MAGNESIUM IN OVER-INNOCULATED CAST-IRON

Magnesium in high-strength cast iron with more than the optimal concentration of spheroidizer is distributed unevenly - the graphite phase is rich in magnesium (the core and to a lesser extent the crab-like branches) and magnesium is precipitated in the grain boundaries of primary structure. The presence of metallic magnesium in overinoculated cast iron was confirmed, and the absence of magnesium carbides in the metallic matrix of slowly cooled magnesium cast iron leads to the assumption that they are formed in the graphite phase. The data obtained permit general conclusions concerning the character and direction of the processes occurring.