Patent ID: 8496046
Filing Date: 2013-07-30
Classification: C21C,C22B,Y02P

Abstract:
1. A method for producing alloy ingot, comprising: a step of charging alloy starting material into a cold crucible in a cold-crucible induction melter, and forming a melt pool of the alloy starting material by induction heating in inert gas atmosphere; a step of continuing the induction heating and adding first refining agent to the melt pool, and then reducing the content of at least phosphorus from among impurity elements present in the melt pool; and a step of forming alloy ingot by solidifying the melt, the phosphorus content of which has been reduced, wherein the first refining agent is a mixture of metallic calcium and flux containing calcium halide; the flux contains calcium fluoride and at least one of calcium oxide and calcium chloride, with a proportion of a total weight of the calcium oxide and the calcium chloride with respect to a weight of the calcium fluoride ranging from 5 to 30 wt %; and a proportion of a weight of the metallic calcium in the first refining agent with respect to a weight of the melt pool before adding the first refining agent is 0.4 wt % or greater.