基于密集冷却工艺的700 MPa级高强带钢减小残余应力研究

目前密集冷却工艺已广泛用于生产高强度带钢，但是该技术冷却速率较快的特点易造成带钢冷却不均匀等问题，导致带钢残余应力过大，进而产生边浪等板形缺陷。本文利用有限元方法，使用ABAQUS有限元软件建立某700 MPa级高强度带钢在密集冷却工艺下的模型，实现温度-相变-应力耦合计算，并进行多个实验验证了模型的准确性。通过修改有限元模型边界条件和初始条件，研究边部遮挡和初始温差对带钢层流冷却阶段产生的残余应力分布的影响规律。对于减小带钢层流冷却过程中产生的残余应力，减小带钢进入层流冷却前的初始温差更加有效。本研究成果经过现场试验验证，可靠性较高，可用于指导该种类型高强带钢生产，以减少带钢的残余应力，提高带钢板形质量。

Research on relaxing the residual stress of 700 MPa high strength strip steel based on intensive cooling technology

Intensive cooling technology is widely used to produce high strength strip steel, but high cooling rate leads to some de-fects, such as shape waves caused by high residual stress. A numerical model was established to achieve a coupling calculation of tem-perature, phase transformation and stress for high strength steel ( 700 MPa ) during intensive cooling. Commercial FEM software ABAQUS was used to build coupled models that verified by a series of experiments. The effects of edge masking and initial temperature difference on the residual stress were studied by modifying initial and boundary conditions. It is concluded that reducing the initial temperature difference is more effective to release the residual stress of strip steel during cooling. Proven by industrial experiments, these research results would be used to lower the residual stress and improve the quality of hot-rolled strips.