High-throughput accelerated corrosion test of Q450NQR1 weathering steel

Abstract

A high-throughput accelerated corrosion set-up was developed to get Q450NQR1 weathering steel specimens of different degrees of marine atmospheric corrosion by controlling various natural factors. The corrosion behavior of weathering steel was studied through in situ analysis methods, namely 3D laser scanner and scanning Micro X-Ray fluorescence (μXRF), and classical test methods such as scanning electron microscopy (SEM), X-ray diffraction analysis (XRD) and weight loss testing. The reliability of the high-throughput accelerated corrosion test method was comprehensively evaluated. The results show that the corrosion mechanism and corrosion rate of the samples in the high-throughput accelerated corrosion testing are basically consistent with the corrosion mechanism in the real marine atmospheric environment. The power functions y2= 4.377t−0.955 and x = 0.00079t1.597 fitting the results of the high-throughput accelerated corrosion testing can predict the corrosion rate of the test material within a period of 30 years. In the process of high-throughput accelerated corrosion, the rust layer comprises γ-FeOOH, α-FeOOH and Fe3O4. With the exposure time increases, the roughness of the rust layer increases, and the self-corrosion potential increases slightly. Cr, Cu and Ni are abundant near the surface of the sample, which increases the binding force between the rust layer and the substrate and improves its corrosion resistance.