Microstructure heritance of metallographic feature in the anodization of carbon steels

•Anodized films reflect the metallographic features of the carbon steels substrate.•Treatment of metallographic structures provides a way of anodized films control.•The methodology could be transplanted into similar alloy systems to prepare functional oxide films. The anodization of several carbon steels with typical metallographic structures were systematically investigated. It was shown that the anodized iron oxide films were inherited from the microstructural characteristics of the original metallographic structure by employing metallographic regulation. Different characteristics of the original metallographic structures could affect the rate of the anodization reaction and determine the thickness of the oxide layer on the substrate. Meanwhile, the connection of nanopore size with the original microstructure of the substrate was also revealed by the statistical analysis of pore size on the anodized iron films. The methodology and techniques could obtain tunable micro-nano structure and might be applicable in similar alloy systems.