| Aluminum and aluminum alloy products have been widely used in various fields for its superior performance. The expansion of aluminum and aluminum alloys has led to the rapid development of aluminum production industry, China’s aluminum production is close to half of the world’s aluminum production. At the same time, the power consumption of China’s aluminum industry is also the first in China’s industrial power consumption. The research shows that the energy utilization ratio of aluminum industry is less than 50%, and the energy saving space is very large. The cathode collector bar as a part of the cathode of aluminum electrolysis industry, is an important part of energy dissipation. The research of cathode collector bar with excellent electrical conductivity has become a hot research topic.In recent years, the research direction of the improvement of the conductivity of the cathode collector bar is mainly about the adjustment of the steel structure and composition, the Composite material and special shaped cathode. This study mainly through the adjustment of the collector bar structure and composition to improve the conductivity of collector bars. By comparing the conductivity and hardness of iron, Q195 and Q235 in different heat treatment, determine the effect of heat treatment temperature on the conductivity and hardness of the materials and the advantages and disadvantages of the three materials under the same heat treatment conditions. 6 groups of alloys, such as Fe-Ti and Fe-Al, were prepared by adding elements Ti, Al and Cu, etc. Metallographic analys is, XRD, SEM and EDS were used to observe microstructure and morphology of the alloys and to determine the composition of the second phase.The results are follows:(1) Heat treatment can improve the electrical conductivity of the metal by eliminating the vacanc ies and dislocations in the metal and increasing the grain size.The grain size of Pure iron, Q195 and Q235 at 850℃holding 2h greater than the grain size of Pure iron, Q195 and Q235 at 850℃holding 2h.The grain size of Pure iron, Q195 and Q235 at 850℃ and 750℃ holding 2h greater than the grain size of non-heat treatment. With the increase of grain size, the conductivity of three materials showed an upward trend.(2) In the same heat treatment conditions,due to the lattice distortion formed by the interstitial solid solution or clearance compound,the conductivity of pure iron is superior to Q195,the conductivity of Q195 is better than Q235.(3) Under the condition of same holding time, with the increase of the heat treatment temperature,the dis location and stress are disappeared in metal crystals and strength decreases,the hardness of pure iron,Q195 and Q235 were tested decreasing trend.(4) Various alloy elements are added to the iron, the grain size become smaller. This is because the addition of alloying elements can prevent the further growth of grain in the process of grain growth.The scattering of carriers caused by solid solution formed by the alloy elements can affect the conductivity of the metal.(5) The effect of Ti element on grain refinement is obvious.The Fe2 Ti phase formed by Ti and Fe can stabilize the hardness of the alloy at high temperature so that the hardness of the alloy at high temperature will not drop too low.(6) Al element and Fe element can form the FeAl ordered phase of B2 type bcc lattice structure structure. The ordered phase can restore the periodicity of the metal crystal and increase the mean free path of the electron, which is beneficial to the improvement of the conductivity of the metal.(7) Ti will be dissolved in the ordered phase in FeAl. This will increase the lattice constant of FeAl ordered phase and the ordered phase is further increased, and then the metal conductivity can be improved.The addition amount of Ti and Al element exists a most benefic ial ratio for the conductivity of the alloy, which needs further research. |
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