INDUCTION MELTING APPARATUS EMPLOYING HALIDE TYPE CRUCIBLE, PROCESS FOR PRODUCING THE CRUCIBLE, METHOD OF INDUCTION MELTING, AND PROCESS FOR PRODUCING INGOT OF ULTRAHIGH-PURITY Fe-, Ni-, OR Co-BASED ALLOY MATERIAL

Title:

Document Type and Number:

WIPO Patent Application WO/2007/063748

Kind Code:

A1

Abstract:

An ultrahigh-purity high-melting metal is melted by induction melting without damaging a crucible even when a smelting agent comprising a halogen compound is used. For the induction melting, an induction melting apparatus is used which has a crucible equipped with tubular segments disposed in a cylindrical arrangement so as to leave a gap of 1.5-15 mm between adjacent tubular segments. A layer of the halide or another compound of a metal element in a specific Group of the Periodic Table has been formed in these gaps and on the inner circumferential surface of the peripheral barrel part. Furthermore, a large ingot of an ultrahigh-purity Fe-, Ni-, or Co-based alloy material can be produced which has impurity levels including (C+O+N+S+P)<100 ppm and Ca<10 ppm. The ingot is produced by conducting primary melting while keeping the molten metal in contact with a flux including a halide, discharging the melt, solidifying it to produce primary ingots, thereafter conducting secondary melting in which the primary ingots are successively melted in a water-cooled copper vessel by the electron beam melting method at a low pressure, and then withdrawing the melt from the outlet side while solidifying it.

Inventors:

KUNII KAZUTAKA
KUSAMICHI TATSUHIKO
NAKAYAMA JUMPEI
KIUCHI KIYOSHI

Application Number:

PCT/JP2006/323238

Publication Date:

June 07, 2007

Filing Date:

November 21, 2006

Export Citation:

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Assignee:

KOBE STEEL LTD (JP)
KUNII KAZUTAKA
KUSAMICHI TATSUHIKO
NAKAYAMA JUMPEI
KIUCHI KIYOSHI

International Classes:

F27B14/10; C04B41/87; F27B14/06; C21C7/00; F27D1/00

Foreign References:

JPH11246919A	1999-09-14
JP2002122386A	2002-04-26
JPH0658672A	1994-03-04
JP2000248310A	2000-09-12
JPH11310833A	1999-11-09
JP2001279340A	2001-10-10

Other References: