Titanium slab for hot rolling, and production method therefor

Abstract

A melted and resolidified layer, which has a depth of at least 1 mm and is obtained by adding, melting, and resolidifying at least one Beta-phase-stabilizing element, is provided to the surface to be rolled of a titanium slab comprising a titanium alloy produced using an electron beam melting method or a plasma arc melting method. The average concentration of the Beta-phase-stabilizing element in a range up to a depth of 1 mm is at least 0.08 mass% but not more than 1.50 mass% higher than the concentration of the Beta-phase-stabilizing element in the parent metal. Powder, chippings, wire, and foil are used as raw materials which include the Beta-phase-stabilizing element. Furthermore, 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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