Random Field Model of Corroded Steel Plate Surface in Neutral Salt Spray Environment

Abstract

The random field model of corrosion depth on steel plate surface in neutral salt spray environment was investigated. 10 groups of specimens were subjected to accelerate corrosion by the neutral salt spray test, and the surface profile of corroded steel plates and the 3D data of corrosion depth were measured by three-dimensional non-contact surface topography instrument. The probability characteristics of corrosion depth were studied and the relationship between the average and the standard deviation of corrosion depth and the mass loss rate were analyzed. The corrosion depth were tested for ergodicity and stationarity and the autocorrelation function model of random field model of corrosion depth was proposed. The results of the study show that the corrosion depth on steel plate surface in neutral salt spray environment conformed to the normal distribution. With the increase of mass loss rate, the average and the standard deviation of the corrosion depth increased. The corrosion depth has ergodicity and stationarity. The random field model of cosine trigonometric function can accurately characterize the distribution of corrosion depth, which prepared the preliminary preparation for the finite element analysis of the corroded steel structure.