热轧薄规格DP600双相钢组织演变

Microstructural evolution of hot-rolled thin-gauge DP600 dual-phase steel

采用MMS-200热模拟试验机对DP600双相钢进行双道次压缩,研究带有中间坯补热工序的无头轧制工艺和常规轧制工艺对试验钢奥氏体组织和变形抗力的影响,并在实验室进行了2种工艺条件下的热轧试验。结果表明,具有中间坯补热工序的无头轧制工艺有利于精轧前奥氏体组织的均匀化,降低钢材的变形抗力,试验钢更易于变形;轧制薄规格双相钢时,中间坯补热工序可以抑制马氏体带状组织的生成,试验钢具有较高的断后伸长率,马氏体含量的增加提高了试验钢的抗拉强度,力学性能满足DP600的标准要求。该研究结果为无头轧制工艺开发薄规格DP600双相钢奠定了理论基础。

The effects of endless rolling process with intermediate billet reheating process and conventional rolling process on the austenite microstructure and deformation resistance of DP600 dual-phase steel were studied by two-pass reduction experiments on a MMS-200 thermalmechanical simulator. The hot rolling experiments of the two processes were carried out in the laboratory. The results show that the endless rolling process with intermediate billet reheating process is beneficial to the homogenization of austenite grains before finishing rolling and the reduction of deformation resistance, which makes the experimental steel more easily deformed. When rolling the thin-gauge dual-phase steel, the intermediate billet reheating process can inhibit the formation of martensite banded microstructures and increase the martensite volume fraction. Under this process, the experimental steel obtained higher elongation and tensile strength, and its mechanical properties can meet the requirements of DP600 standard. The research results laid a theoretical foundation for the development of thin-gauge DP600 dual-phase steel by endless rolling process.