Papers by Keyword: Continuous Cast

Abstract: Favorable features such as finer particles and supersaturated solid solution are characterized in continuous casting. In this study, difference of recrystallization behavior was mainly evaluated on two intermediate annealing conditions in continuous cast Al-Mn alloy. One annealing condition was air furnace annealing which corresponds to batch type annealing and is conventionally used to anneal aluminum alloys. Another one was salt bath annealing which simulates CAL type annealing, which is characterized by shorter holding time with rapid heating and cooling. With consideration for application to fin stock in heat exchanger, heat treatment simulating brazing at 600°C was carried out on cold rolled sheets after respective intermediate annealing. After the brazing heat treatment, superior tensile strength and coarser grain structure were attractively obtained with the salt bath intermediate annealed fin. This tensile strength was correlated with much finer particles and more solid solution confirmed after the salt bath intermediate annealing. The coarser grain structure would be brought by changing in recovery and recrystallization behavior during brazing heat treatment.

Abstract: The three layers clad strip was fabricated by a tandem positioned vertical type twin roll casters. The effect of the casting conditions of the overlay strip on the interface between the base strip and the overlay strip was investigated. The temperature of the molten metal, roll-load and solidification length were chosen as the casting conditions. Base strip was AA8079 and overlay strip was AA6022. The proper melt temperature of the overlay strip was above the liquidus line of the base strip. The proper roll-load, which was lower than rolling, was existed. There was not clearance at the interface when the solidification length was appropriate.

Abstract: An investigation was conducted on the softening behaviour of cold rolled continuous cast (CC) AA5754 Al alloy and compared to the results for the ingot cast (IC) material. The present study suggests that the CC material exhibits greater resistance to softening as compared to the IC AA5754 for the same amount of cold deformation. The differences in the softening kinetics become more noticeable with increasing level of cold deformation and from a processing point of view can be attributed to the absence of the homogenization stage during the processing of the CC material. Resistivity measurements were carried out during the annealing treatment of the CC materials to examine the possibility of concurrent precipitation, which could potentially retard the softening kinetics for these materials. In addition, the current research reveals that the CC material produces a finer recrystallized grain size as compared to the IC material.

Abstract: Factors controlling the recrystallization of a continuous cast Al-Fe-Ni alloy were investigated by analyzing microstructure, grain structure, texture, and electron backscattering patterns. The texture of an as-rolled sample heated at 400°C was similar to that of a sample at the reduction ratio of 50% after intermediate annealing at 550°C. The as-rolled samples had a strong (213)[36-4] (S-type) orientation that was changed to a strong (130)[3-12] (QQ-type) orientation by heating at 400°C. This recrystallization looks like continuous recrystallization. Discontinuous recrystallization due to particle-stimulated nucleation is suppressed by the fine dispersion of Al-Fe-Ni-Si particles that form during casing and intermediate annealing, and stabilize the grain and subgrain structure. We think that a course initial grain structure and moderate level of strain level are the important factors promoting continuous recrystallization in this alloy.