Analysis The Character Of Corrosion Surface Morphology Of Cable Steel Wire

The cable is the key structural component of cable-supported bridges,and its service safety directly affects the operation safety of the whole bridge,and its durability often directly affects the overall service life of the bridge.In engineering practices,the corrosion of cables is the most direct factor affecting the safety and durability of cables.A large number of studies on corrosion of steel structures have shown that pitting corrosion is the key mode affecting the mechanical properties of damaged steel members.In order to study the corrosion effect of cable steel wire,it is necessary to analyze the pitting morphology and its parameter characteristics in detail.In this paper,we carry out the indoor simulated accelerated corrosion test to aim at the corrosion development law of cable steel wire,we studied the distribution characteristics of pitting pits on the surface of steel wire under different corrosion times,and extracted the morphological characteristics of pitting images.The main research results are as follows:(1)Through the statistical analysis of the number of corrosion pits on the surface of steel wire in the laboratory accelerated corrosion test,we got the statistical data of the number of different types of corrosion pits under different corrosion time lengths,and established the distribution model of each type of corrosion pits to the corrosion time.(2)By measuring and counting the three-dimensional dimension data of the corrosion pit on the surface of corroded steel wire,combining the fractal theory,using the parameter estimation and K-S hypothesis test,we studyed the three-dimensional dimension distribution characteristics of the corrosion pit.The results show that the length and width of pitting pits obey logarithmic normal distribution,and the distribution of the length,width and depth of pitting pits has fractal features under different corrosion time lengths,and the shape of pitting pits on the steel wire surface is generally short,narrow and middle-shallow.(3)Collecting the image of corrosion steel wire surface as the research object,based on the theory of fractal theory,using computer image processing technology,we extracted and analyzed the gray scale features of the corrosion image.The results show that the corrosion image of test steel wire sample has fractal features,the digital matrix of the image reflects the distribution of the gray scale of the corrosion image,and the average gray scale of the corrosion image was linearly correlation with the corrosion time length;(4)Based on the binarization images to extract feature,we established the correlation between corrosion image features and corrosion time length.The results show that the fractal dimension changes with time was consistent with the actual corrosion situation,which can be used to characterize the corrosion severity of steel wires.