This work investigated the microstructure, mechanical properties and corrosion behavior of dual-phase (DP) steel after different intercritical quenching treatment and compared the results with commercial AH32 steel. The results indicate that the microstructure of all tested DP steels was composed of lath martensite and polygonal ferrite. As the temperature increased from 750 to 850 °C, the martensite lath became slender, whereas martensite volume fraction (V_m) increased from 53 to 71%. The change in the morphology and content of martensite not only led to an increase in hardness and yield strength, but also to a decrease in the plasticity and impact toughness, which was consistent with the mixture law. However, the ultimate tensile strength did not increase but declined, which was an unusual behavior. It was related to the micro-void coalescence fracture mechanism caused by the ferrite/martensite interface decohesion. Moreover, the increasing temperature led to the enhanced galvanic effect between ferrite and martensite, accelerating the corrosion rate of DP steels in a 3.5% NaCl solution. A comparison of all results in our work indicates that DP750 steel with 53% martensite had excellent comprehensive properties.

这项工作研究了双相（DP）钢在经过不同的临界淬火处理后的组织，力学性能和腐蚀行为，并将结果与​​商用AH32钢进行了比较。结果表明，所有测试的DP钢的显微组织均由板条马氏体和多边形铁素体组成。当温度从750°C升至850°C时，马氏体板条变得细长，而马氏体体积分数（V _m）从53％增加到71％​​。马氏体形态和含量的变化不仅导致硬度和屈服强度的增加，而且导致塑性和冲击韧性的降低，这与混合定律是一致的。但是，极限抗拉强度没有增加而是下降了，这是不寻常的行为。这与铁素体/马氏体界面脱粘引起的微孔聚结断裂机理有关。此外，温度升高导致铁素体与马氏体之间的电化作用增强，从而加速了DP钢在3.5％NaCl溶液中的腐蚀速率。我们工作中所有结果的比较表明，马氏体含量为53％的DP750钢具有优异的综合性能。