Arc restarting process after outages in vacuum consumable melting process of titanium and titanium alloys

Abstract

The invention relates to an arc restarting process after outages in the vacuum consumable melting process of titanium and titanium alloys. The process comprises the steps of raising the melting current rapidly to 75% to 80% of the normal melting current, and maintaining the melting current when an arc is restarted after smelting is interrupted; and keeping for 2 to 3 minutes after the edge of a melting pool reaches the crucible wall and rapidly raising the melting current at the moment to the normal melting current. The arc restarting process after outages in the vacuum consumable melting process of titanium and titanium alloys has the advantages that the total arcing time is shortened greatly, the gap produced between a casting ingot and the crucible wall after the cooling volume of the casting ingot is contracted is reduced, and an internal shrinkage cavity formed by the cooling solidification of the casting ingot is avoided; and keeping the melting current for a while when the melting current achieves 75% to 80% of the normal melting current, hence, melting speed of electrodes and the solidified melting pool can be controlled accurately, a large number of melting liquids are prevented from producing instantaneously to flow into the gap between the casting ingot and the crucible wall or to cause cold shut defects.

Description

technical field [0001] The invention relates to the field of vacuum self-consumption smelting of titanium and titanium alloys, and more specifically relates to a process for restarting arcing after power failure during the vacuum self-consumption smelting process of titanium and titanium alloys. Background technique [0002] During the vacuum consumable smelting process of titanium and titanium alloys, the smelting is often interrupted due to various reasons, and the molten pool will cool and solidify rapidly at this time. When the conditions permit, it is necessary to re-send the arc and start the melting again. But at present, the arcing process is mainly aimed at the arcing of the electrode on the bottom pad of the crucible at the beginning of smelting, which requires a rapid increase of the melting current (generally 1-2KA / min) to the normal melting current, the purpose of which is to quickly establish a molten pool and reduce the bottom The impurity content of the ingo...

AI Technical Summary

Problems solved by technology

[0006] The object of the present invention is to provide a method that can avoid the difficulty of removing the ingot when the ingot is out of the furnace due to the unreasonable control of the arc starting process when the arc is restarted after the interruption of the vacuum self-consumption smelting process of titanium and titanium alloys, and the ingot at the smelting interruption position during forging. The process of restarting the arc after a power failure in the vacuum self-consumption smelting process of titanium and titanium alloys caused by large cracks that cannot continue forging or even scrapping the part of the ingot