Titanium billet for hot rolling and its manufacturing method

Abstract

On the surface of the titanium slab containing the titanium alloy produced by the electron beam smelting method or the plasma arc smelting method, which becomes the rolling surface, there is a molten and resolidified layer within a depth of 1 mm or more, and the molten and resolidified layer is One or two or more β-phase stabilizing elements are added, melted and resolidified, and the average value of the concentration of β-phase stabilizing elements within the range up to a depth of 1mm is higher than that in the base material in mass % The concentration of the β-phase stabilizing element is higher by 0.08 mass % or more and 1.50 mass % or less. As raw materials containing β-phase stabilizing elements, powders, chips, wires, and foils are used. In addition, electron beam heating and plasma arc heating are used as means for melting the surface layer.

Description

technical field [0001] The present invention relates to a method for producing a titanium slab for hot rolling including a titanium alloy, and in particular to a titanium slab capable of maintaining a good surface shape after hot rolling even if blanking steps such as blooming and forging are omitted, and a method for producing the same. Background technique [0002] Titanium materials are usually made of sponge titanium and titanium waste as raw materials, and are smelted by non-consumable electrode arc melting method, electron beam melting method, plasma arc melting method, etc., so as to form titanium ingot (titanium billet). In the non-consumable arc melting method, a compact obtained by press-molding sponge titanium is used as an electrode, and the electrode and the mold are subjected to arc discharge to melt the electrode itself, and cast in the mold to obtain an ingot. Therefore, the discharge between the mold and the electrodes must be performed uniformly, so that th...

AI Technical Summary

Problems solved by technology

In order to remove surface flaws generated during hot rolling, it is necessary to use pickling as a subsequent process to increase the amount of melting on the surface of the hot-rolled material, and the yield rate deteriorates accordingly, and there is concern about cost increases

[0005] Therefore, for titanium ingots manufactured by electron beam melting method and plasma arc melting method, on the one hand, it is expected to improve the cost by omitting blanking processes such as rough rolling and forging. , which hinders the practical application of titanium billets that omit the billet opening process

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