Effect Study Of Ultrasonic On Lead Alloy Continuous Cast-rolling Strip’s Performance

Lead alloy sheet is mainly used in lead-acid batteries and industrial electrolyzer anode plate. With the development of the auto industry and the wet smelting technology, the use of lead alloy sheet will continue to grow. The member of our group Zhang Jia fu, has carried out the simulation and experimental study of the lead alloy dual-roll continuous casting temperature field, and the results show that smooth surface, good mechanical properties of lead alloy strip can be obtained by continuous casting method. In this paper, ultrasonic wave is applied to the casting processing of lead alloy based on the the common casting of the lead alloy and we applied simulation software ANSYS to simulate the temperature field of the casting process. We got the best process parameters of Lead alloy plate ultrasonic casting through a lot of simulation and finally studied the performance of the ultrasonic casting lead alloy plate by experiments. The main contents of this article are as follows:(1) Analyzed the ultrasound basic theory, basic effects, as well as the effects to metal solidification crystallization process, providing a theoretical basis for the simulation and experiment.(2) Described the basic principle of heat transfer and the basic process of ANSYS thermal analysis, established the three-dimensional model of cast-rolling zone and analyzed the relationship of the lead alloy density, viscosity, specific heat capacity, thermal conductivity and temperature. Defined the boundary conditions of the entrance of the model, ear, mouth cast, roll, and the exit boundary. Converted the ultrasound into heat flux and vibration function equation boundary conditions upon the entrance by the law of conservation of energy, and finally successfully simulated the temperature field of the lead alloy ultrasonic cast-rolling.(3) Contrasted the ultrasound cast-rolling and ordinary cast-rolling and found that the temperature at the entrance of ultrasonic casting increased slightly, but the temperature of the exit of the ordinary roughly equal. The temperature distribution in the width direction of ultrasonic cast-rolling is essentially the same and in the longitudinal direction it reached a steady state faster than the ordinary cast-rolling. Studyingthe effects of different process parameters on the ultrasonic cast-rolling, the simulation results show that, in the case of the200w ultrasonic power, the best cast-rolling temperature is380℃～400℃, the best casting speed is1.2m/min～1.6m/min. Measured the actual plate temperature with Fluke Ti45thermal imager, and found that the experimental results and simulation results are basically the same which proved that the temperature field of finite element model and boundary conditions of Roll casting zone is correct.(4) Contrasted the microstructure ultrasonic cast-rolling lead alloy strip and ordinary casting lead alloy strip, the results show that the average grain size (diameter) the ordinary cast-rolling lead alloy plate is120μm and the ultrasonic cast-rolling is80μm. The experiment proved the the ultrasonic can refine grains and homogenize structrures.(5) Further analyzed the mechanical properties of the two cast-rolling strips and found that mechanical properties of ultrasound cast-rolling lead alloy plats are better than that of ordinary cast-rolling, the tensile strength σb, yield strength σ0.2and elongation respectively increased by11.30%,22.15%and21.74%, while the impact strength and flexural strength is basically unchanged.(6) The corrosion resistance of ultrasonic cast-rolling lead alloy plate is better than that of the ordinary cast-rolling one.The XPS experiment shows that the oxide impurity content of ultrasonic casting plate surface is lower than that of ordinary cast-rolling one. This is because the ultrasound brought the oxide impurity into the inside of lead melt, so that the oxide content in the stereotype increases and the corrosion resistance is reduced.