加速腐蚀环境下高强耐候钢Q450NQR1的耐蚀性能研究

Research on Corrosion Resistance of High Strength Weathering Steel Q450NQR1 in Accelerated Corrosion Environment

Q450NQR1是以Cu,Cr,Ni合金化为主的屈服强度达450 MPa以上的高强耐候钢,其耐大气腐蚀性能是决定使用性能的重要指标之一。通常利用加速腐蚀试验采用失重法表征耐候钢的耐大气腐蚀性能。通过周期浸润模拟加速腐蚀试验,对比研究了高强耐大气腐蚀钢Q450NQR1和普碳钢Q345qD的加速腐蚀性能,并用XRD对锈层的相组成进行了分析。结果表明:在试验条件下,Q450NQR1的腐蚀失重量和失重速率明显低于普通碳钢Q345qD。Q450NQR1表面锈层主要由保护性较好的α-FeOOH相组成,该锈层为基体提供了良好而稳定的保护作用。

Q450NQR1 is a kind of high strength weathering steel beating Cu, Cr, Ni and other alloying elements, Its yielding strength is above 450 MPa, and its atmospheric corrosion resistance plays an important role in its applications. Usually, corrosion resistance of weathering steels is evaluated by the weight-loss method in an accelerated corrosion test. The accelerated corrosion properties of high strength weathering steel Q450NQR1 are studied and compared with mild carbon steel Q345qD by means of the periodical immersion cyclic corrosion test, and the phase constitution of rust layers is analyzed by XRD. The results show that under the testing conditions the weight losses and average corrosion rates of Q450NQR1 are remarkably lower than those of Q345qD. The rust layer formed on the Q450NQR1 mainly consists of protective α-FeOOH, which provides a better and stable protection from further corrosion of the substrate.