【正文】 rural countryside of atmospheric corrosion of mild steel。 was also suggested that i, of copper in the collective and the rust layer formed between the copper oxide as the main ponent of the barrier layer, which barrier layer and the collective bination of solid and thus has a better protective effect . Was also suggested that alloying elements such as copper and phosphorus changes the rust layer of moisture absorption, and thus help to improve corrosion resistance. These statements indicate that rust layer of copper can improve the structure and protective properties, it is likely that these effects also exist. P: phosphorus in steel is usually regarded as harmful elements。 of copper when the steel reached , its corrosion rate is gradually balanced. Studies have shown that copper and manganese, titanium and other elements of the pound to add, to the humid atmosphere, oceans and corrosive chemicals in the atmosphere has obvious superposition effects. Corrosion test results show that copper steel corrosion rate lower than the A3 steel more than 50%, while the Food and experiments show that the corrosion resistance of copper steel corrosion test data is better than. In addition to copper series, China39。s surface, oceans are not only an inexhaustible resource of human treasure, but also a natural channel for contacts between countries. Steel is a marine development, maritime transport and naval construction of basic engineering materials, dosage significantly. Because of the corrosive seawater and to the deepsea exploration and development of the scientific needs of seawater corrosionresistant steel research, trial, production and application of universal attention by the countries in the world. the marine environment and its effect on the corrosion of steel The marine environment is very plex, and its chemical, physical, biological and other factors with the different waters and seasonal change. Therefore, the steel corrosion in the marine environment, not only by the chemical position of steel and other materials and surface condition factors, while being under the control of the marine environmental conditions. Typical of the marine environment can be divided into the oceanatmosphere zone, splash zone, tidal range area, fullimmersion zone and mud areas, while the seawater immersion district is divided into shallow waters, the continental shelf areas and deepsea areas. lowalloy steel alloy elements on corrosion The alloy elements in seawater corrosionresistant lowalloy steel in the role, so far have been quite a lot of coverage, but the conflicting and erroneous, it is a lot of areas of agreement. Was mainly due to the environmental conditions, the bination of alloying elements, the length of exposure time or the different test methods for this. Therefore, in discussing the role of alloying elements, it must proceed from reality. There was a lot of metallurgical workers hope to develop into a corrosion resistance in all sea areas can be lowalloy steel, but because of alloy elements in the role of different sea areas there are differe。s steel, due to the full capacity of China39。s resistance to atmospheric corrosion of lowalloy steel Atmospheric corrosionresistant lowalloy steel in China the system development work began in coppercontaining steel. As early as 1962, Wuhan Iron and Steel Company namely, highstrength lowalloy copper studies, and in 1964, Wuhan Iron and Steel Plant in the trial of the use of openhearth steel used to manufacture 16MnCu tankers, and later at the bridge, vehicles and promote the use of chemical containers So far, 20 steel satisfied standard copper production. 15 years, three kinds of atmospheric environment through the 10 pilot sites corrosion test, copper steel proved the performance in different environments. In the dry sand areas, steel copper content of % of the corrosion rate has stabilized。 Oceanic and Atmospheric corrosion of steel is the biggest. Air pollution in rural areas due to a lesser extent, affecting a major factor in corrosion of steel is precipitation, annual mean temperature and relative humidity. Corrosion of steel in the atmosphere is due to the surface of steel is conducive to the formation of the wet film electrochemical reaction, resulting in corrosion to proceed. Industrial atmosphere of the steel corrosion rate of the influencing factors, primarily in the pollution of the atmosphere position and content, such as sulfur dioxide. In the atmosphere is also inevitably contain moisture, which greatly increased the corrosion of steel. Steel corrosion in the marine atmosphere is much more serious than the former two kinds of environments, mainly because of the oceanatmosphere contains a large number of chloride particles, such as the sea fog particles falling in the steel surface, forming a layer of electrolyte of the wet film . Just in the marine atmospheric corrosion by the high plane distance is the proximity and the coastline, wind speed, wind direction and other factors. Nightside is usually steel surface corrosion than steel Yang greater degree, because rain can put a positive salt washed out. In order to prevent atmospheric corrosion of steel, usually paint or metal plating, so that the steel surface and moist air separation, but this surface treatment is not once and for all. The past 2030 years, the world39。 the higher the carbon content, the greater the impact of heat treatment. This is because with the increase in carbon content of steel is also a corresponding increase in cementite, different heat treatment systems, the number of cementite precipitates is different from carbon as the cathode of a mixture of carbon steel for nonpassive system, the cathode efficiency increases, will inevitably lead to an increase in corrosion rate. In the carbon con