Casting method for active metal

Patent metadata

Field	Value
Publication number	US-10981222-B2
Application number	US-201716468499-A
Country	US
Kind code	B2
Filing date	Dec 5, 2017
Priority date	Dec 13, 2016
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

A casting method of an active metal includes, in an induction melting furnace using a water-cooled crucible, tapping a molten metal into a mold from a tapping hole provided at a bottom of the water-cooled copper crucible to cast an ingot of the active metal. In conducting the casting under a casting condition in which the ingot has a diameter (D) of 10 mm or more and a ratio (H/D) of an ingot height H to the ingot diameter D of 1.5 or more and a weight of the molten metal tapped in the casting is 200 kg or less, a temperature of the molten metal in the casting is set to be higher than the melting point of the active metal and a casting velocity V (mm/sec) is controlled to satisfy V≤0.1H in relation with the ingot height H by adjusting an opening diameter of the tapping hole.

First claim

The invention claimed is:

1. A casting method of an active metal, the method comprising:
in an induction melting furnace using a water-cooled crucible, tapping a molten metal into a mold from a tapping hole provided at a bottom of the water-cooled copper crucible, thereby casting an ingot of the active metal,
wherein the casting is conducted under a casting condition in which the ingot has a diameter (D) of at least 10 mm and a ratio (H/D) of an ingot height H to the ingot diameter D of at least 1.5, and a weight of the molten metal tapped in the casting is 200 kg or less, and
wherein a temperature of the molten metal in the casting is higher than a melting point of the active metal and the casting is conducted while a casting velocity V (mm/sec) that is a velocity at which the casting proceeds in the mold is controlled to satisfy V≤0.1H in relation to the ingot height H by adjusting an opening diameter of the tapping hole.

2. The method of claim 1 , wherein the active metal is at least one selected from the group consisting of a titanium (Ti)-based, zirconium (Zr)-based, vanadium (V)-based, and chromium (Cr)-based alloy.

3. The method of claim 1 , wherein a yield of a non-defective ingot in the bottom-tapping method is up to 80%, wherein the yield of a non-defective ingot represents a ratio h/H of a height h of a place where a shrinkage cavity C is not generated inside the ingot to a height H of the ingot.

4. The method of claim 2 , wherein a yield of a non-defective ingot in the bottom-tapping method is up to 80%, wherein the yield of a non-defective ingot represents a ratio h/H of a height h of a place where a shrinkage cavity C is not generated inside the ingot to a height H of the ingot.

Assignees

• Kobe Steel Ltd

Inventors

• MORIKAWA Yuzo
• MATSUWAKA Daisuke
• Ishida Hitoshi
• Ikeda Shushi

Classifications

• B22D7/00

  Casting ingots, {e.g. from ferrous metals}(equipment for conveying molten metal B22D35/00) · CPC title

• B22D27/04

  Influencing the temperature of the metal, e.g. by heating or cooling the mould · CPC title

• F27B14/06

  heated electrically, e.g. induction crucible furnaces with or without any other source of heat (F27B14/04 takes precedence) · CPC title

• B22D13/00

  Centrifugal casting; Casting by using centrifugal force · CPC title

• F27B2014/0837

  Cooling arrangements · CPC title