COMPOUND GRAPHITE SPHEROIDIZING AGENT

摘要

PROBLEM TO BE SOLVED: To provide a compound graphite spheroidizing agent by which reaction can be held gentle and additive quantity can be made to a value equal to or lower than that in the case of treatment using conventional graphite spheroidizing alloy and further the amount of generation of magnesium-silicate- type dross and slag can be minimized. SOLUTION: The inside of a sheath material 3 composed essentially of iron is filled with a filler 2 composed of Si-Mg alloy. The weight ratio of the Mg component in the filler 2 is made to 3-15% based on the whole of the compound graphite spheroidizing agent, and the balance of the filler 2 is composed essentially of Si and iron. Further, the weight proportion of the sheath material 3 is made to >=60% based on the whole of the compound graphite spheroidizing agent, and also the weight ratio of the Si component based on the whole of the compound graphite spheroidizing agent is made to <=20%.