板条贝氏体中少量铁素体对高强钢强韧性的影响

以一种低成本高强钢为研究对象，对其实施了不同冷却模式的TMCP工艺实验，并利用光学显微镜、拉伸试验机、冲击试验机对其组织与力学性能进行了研究.实验结果表明:通过相变强化和在两相区的保温处理，在以板条贝氏体为主的实验钢组织中引入少量铁素体，使其拥有高强度、高冲击韧性等综合力学性能.在同类工艺条件下，试验钢的抗拉强度、屈服强度以及屈强比随终冷温度降低而升高，延伸率和断面收缩率随终冷温度降低而降低.

Effects of the Small Amount of Ferrite in Bainite Laths on the Strength and Toughness of High Strength Steels

A low cost high strength steel was studied by TMCP processing under different cooling modes， the microstructures and mechanical properties were investigated by the optical microscope， tensile testing machine and shock testing machine respectively. The results showed that the transformation strengthen and insulation treatment in two phase region can bring a small amount of ferrite into the tested steel， in which the original microstructure is mainly lath bainite， that leads to high strength and high shock toughness of the tested steel. Under the similar conditions， the tensile strength， yield strength and yield ratio increase while the elongation and reduction of area decrease with the decrease of the final cooling temperature.