Investigation of Batched Annealing Process in NbTi Bearing High Strength Cold Rolled Steel Sheet

摘要

The batched annealing process of high strength cold-rolled sheet containing Nb&Ti has been investigated. Firstly, by testing the hardness of the samples after annealing, the recrystallization curve and the recrystallization temperature are obtained. Secondly, according to different annealing parameters, the experiments of the batch-annealing are simulated in the laboratory. Thirdly, by testing the properties of the samples and analyzing the microstructures of the steel, we find that the recrystallization temperature of Nb&Ti alloyed steel is about 650°C. With the increment of annealing temperature and time, the strength and hardness decrease, and elongation increase. When the annealing temperature is higher than the recrystallization temperature, the influence of annealing time on the properties of the steel is less than annealing temperature. According to the recrystallization temperature, the actual parameters of the batch-annealing have been processed in the cold rolling manufactory of WISCO, and the satisfied properties are obtained.