Analysis of the mechanism of chromatic aberration defects on A510L surface of high quality hot rolled pickled strip

Abstract

In view of the chromatic aberration defects on the surface of hot-rolled strip A510L after pickling, the microscopic morphology features of different positions of the pickled strip surface were compared and analyzed by using laser confocal microscope (CLSM), and the generation mechanism of chromatic aberration defect was studied by using high-resolution scanning electron microscope and energy dispersive spectrometer (EDS). The results show that the main cause of surface chromatic aberration defects on the surface of pickling plate A510L is closely related to the interface state between hot-rolled raw material substrate and iron oxide scale, and there is an enrichment area of Fe₂SiO₄/FeO binary eutectic near the hot-rolled raw material substrate and iron oxide scale, and the proportion of Fe₂SiO₄ is higher as it approaches the strip steel matrix, and Fe₂SiO₄/FeO has a strong pinning effect, which leads to the adhesion of iron oxide scale. The existence of Fe₂SiO₄/FeO changes the structure of carbon steel iron oxide scale, which makes the bonding force between iron oxide scale and strip steel matrix increase the difficulty of pickling process, and finally presents the surface chromatic aberration defects after pickling.