The Influence and Mechanism of Rare Earth Elements on Microstructure and Performance to Welded Titanium Cathode Drum for Copper Foil Production

摘要

In this paper, we introduce a new method to get welded drum cathode that rare earth additions applies in welded zone forms refining grain. During the welding operation, special steps such as bending, welding surfacing, forging to flat and anneal were applied to benefit for grain grade. Upon complete formation of the weld, the formed and welded trip of titanium is subjected to a heat treating cycle that includes an anneal process. Preferably, the strip of titanium metals open a special groove and the weld metal that: is used to form the weld zone comprise an addition agent such as yttria. Additionally,a drum cathode made in accordance with the principles in this study can be produced at considerably lower costs than a seamless drum cathode for there is no need for the expensive capital equipment that is employed in the production of seamless drum cathodes. The experiment shows that proper amount rare earth oxide added in weld zone can refine the microstructure,increase ratio of acicular a'and even α'' phase in the microstrcture,enhance low temperature notch toughness and reduce diffusible hydrogen. The study shows that rare earth oxide added in weld wire can be decomposed into high activity rare earth atoms at high temperature of droplet stage. This activey rare earth atom can be transferred to welding pool and engaged in welding metallurgy reaction. Therefore, the method of adding rare earth oxide in weld wire to transfer rare earth element is an economical and effective method. Using this method, we can make full use of the beneficial effect of rare earth oxide in welding material. The mechanism and influencing factors of rare earth oxide transferred from weld material to weld pool were also discussed.