Test method for improving surface quality of microalloyed steel continuous casting slab

Abstract

The invention relates to a test method for improving the surface quality of a microalloyed steel continuous casting billet. The method comprises the following steps that an unconventional high-temperature tensile test is designed through a thermal simulation testing machine by mastering the temperature fluctuation of the continuous casting billet in a withdrawal and straightening process; and the continuous casting process is adjusted by simulating data of the casting blank in two states of temperature fluctuation and stretching in the withdrawal and straightening process, the obtained data better conforms to the actual rule, and the method has higher reference value for casting blank crack control. The temperature fluctuation period t is determined according to the casting blank pulling speed and the roller diameter, the temperature fluctuation T is determined according to a continuous casting tool, + / -T up-and-down fluctuation circulation is achieved within the time t at different stretching temperatures, and therefore data closer to the actual production technology is obtained to adjust the straightening temperature and the like. And finally, the continuous casting straightening temperature is formulated by analyzing and comparing high-temperature thermoplasticity under different parameters and according to the principle that the area shrinkage is higher than 60% and is a plastic area, and the area shrinkage is lower than 40% and is a brittle area.

Description

technical field [0001] The invention belongs to the technical field of wire rod preparation for cold heading steel, and in particular relates to a wire rod for cold heading steel with low strength and high plasticity and annealing-free cold heading steel and a manufacturing method. Background technique [0002] The third brittle temperature range of the continuous casting slab is an important factor affecting its surface quality, and the lower plasticity increases the tendency of the slab to crack during the bending and straightening stages. In order to avoid the occurrence of cracks, the continuous casting process of the slab is usually formulated according to the high temperature thermoplasticity curve of the steel, especially the straightening temperature is formulated to avoid the brittle zone. However, in the production of microalloyed steel, the occurrence of surface cracks cannot be avoided, because the third brittle temperature range of microalloyed steel is generall...

AI Technical Summary

Problems solved by technology

The conventional high-temperature thermoplasticity measurement scheme does not consider the influence of temperature fluctuations. Therefore, for microalloy steel continuous casting stretching and straightening process, considering the temperature fluctuation system is the key factor to accurately obtain thermoplasticity, and it is of great significance to improve the surface quality of slabs

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