Analysis Of Corrosion Characteristics And Influencing Factors Of Coastal Landscape Facilities In Tropical Coastal Atmosphere

Anions and cations in the coastal atmosphere are the main pollutants that affect the corrosion of coastal facilities.In order to understand the corrosion of coastal landscape facilities in the coastal atmosphere,the distribution characteristics of corrosive ions in coastal aerosols,and the distribution characteristics of corrosive ions on the surface of landscape facilities.This work investigated the corrosion status of coastal landscape facilities in the three tropical coastal cities of Shenzhen,Zhuhai and Zhanjiang in Guangdong Province,focused on the investigation of the distribution characteristics of corrosive elements in the atmospheric aerosols in the three survey areas in Zhanjiang City（Zhanjiang Seaside Park,Donghai Island Longhaitian Bathing Beach,Baosteel Zhanjiang Iron and Steel Base）,and discussed and analyzed the factors affecting the corrosion failure of coastal landscape facilities.The main conclusions are as follows:（1）The marine atmosphere is the most serious atmospheric environment that affects facilities corrosion.The landscape facilities exposed to the marine atmosphere of Zhanjiang,Zhuhai and Shenzhen all have different degrees of corrosion.Corrosion is mainly distributed in welded parts,screw connections,grooves,gaps,inlaid parts,steel turning parts,component connections,and ground connections,etc.Among the 168types of landscape facilities surveyed,the average frequency of crevice corrosion of landscape facilities is 66.6%,and the average frequency of weld corrosion is 53.2%.Crevice corrosion and weld corrosion are the main types of corrosion of landscape facilities;The corrosion degree of landscape facilities is closely related to the distance from the landscape facilities to the sea and the orientation of the landscape facilities.The corrosion degree of the landscape facilities decreases with the increase of the distance from the sea,and the corrosion degree of the landscape facilities toward the sea also increases with the distance from the sea.The sea distance increases and decreases,and the ratio of the corrosion degree of the landscape facilities toward the sea and the back sea surface increases with the increase of the distance from the sea.It shows that the corrosion degree of landscape facilities decreases with the increase of the distance from the sea,and the corrosion degree of landscape facilities toward the sea also decreases with the increase of the distance from the sea.（2）The distribution characteristics of marine air pollutants in Zhanjiang City show seasonal differences.Cl^-and SO₄^2-are high in summer,and NO₃^-and PO₄^3-are high in autumn and winter.The correlation analysis results between the concentrations of various corrosive ions show that the concentration of Cl^-and SO₄^2-are positively correlated,and the concentration of NO₃^-and PO₄^3-are positively correlated;Meteorological elements（temperature,relative humidity,atmospheric pressure and wind speed）have an important effect on the distribution of atmospheric pollutant concentrations;Zhanjiang’s temperature,humidity and corrosive media together characterize the high corrosiveness of the Zhanjiang coastal atmosphere.（3）The ions deposition rate on the surface of coastal landscape facilities differs in sampling season,distance from the sea and facility orientation.As far as the sampling season is concerned,Cl^-,NO₃^-,SO₄^2-,Na⁺and K⁺show high deposition rate in winter,Mg²⁺shows high deposition rate in summer,and Ca²⁺shows high deposition rate in spring;In terms of the distance from the sea,the deposition rate of the anions Cl^-,NO₃^-and SO₄^2-and the cations Na⁺,K⁺,Mg²⁺,Ca²⁺shows a downward trend as the distance from the sea increases;In terms of orientation of facilities,the deposition rate of landscape facilities on the whole is towards the sea>behind the sea,but with the increase of the distance from the sea,the difference between the settlement rate of landscape facilities towards the sea and behind the sea decreases.The surface corrosive ions deposition rate of coastal landscape facilities is closely related to the season,the distance from the sea and the orientation of facilities.（4）The deposition rate of corrosive pollutants on the surface of Zhanjiang coastal landscape facilities is simultaneously affected by meteorological factors（temperature,relative humidity,atmospheric pressure,wind speed,etc.）and environmental media factors（corrosive ions in the atmosphere）.Combining the surface pollutant deposition rate of Zhanjiang coastal landscape facilities and the analysis of the corrosion status of coastal landscape facilities,it is shown that the surface pollutant deposition rate of Zhanjiang coastal landscape facilities and the corrosion area of landscape facilities vary with the distance and orientation from the sea.The results show that the farther the facilities are away from the sea,the lower the deposition rate of corrosive pollutants on the surface of facilities,and the higher the proportion of small area corrosion;On the whole,the deposition rate of corrosive pollutants towards the sea is higher than that of the back sea,and the proportion of large-scale corrosion towards the sea is also higher than that of the back sea.The deposition rate of pollutants on the surface of facilities can reflect the corrosion degree of facilities to a certain extent.