Numerical simulations for time-dependent corrosion surfaces of unpainted carbon steel plates in atmospheric corrosive environments using spatial statistical techniques

Many severe corrosion damages have been reported in steel structures constructed in a period of high economic growth. To ensure the safety of such structures, it is important to devise a method how corrosion develops in the service. However, method of predicting such behavior has not yet been established. In this research, semi-vari-ogram analyses were carried out on time-dependent corrosion surfaces of unpainted steel plates exposed to atmospheric environment to clarify the spatial autocorrelation structures and their time-dependence. In addition to this, by using the autocorrelation structures and an ordinary kriging technique, method of spatial statistical simulation for the time-dependent corrosion surfaces in various atmospheric corrosive environments was proposed. Moreover, example of the relationship between mean and maximum corrosion depths was proposed on the basis of simulated results of time-dependent corrosion surfaces of unpainted carbon steel plates.