金属腐蚀与防护英文专题

金属腐蚀与防护英文专题内容摘要：

rflow and light of the different corrosion rate can be / a varied between. But the majority of cases, / a. Corrosion in aqueous solution was more plex than the atmosphere, most acid, alkali, salt water solution are highly corrosive to carbon steel. Only the strong oxidation of concentrated sulfuric acid, dilute acetic acid, sulfur, saltpeter mixed acid, alkaline hydroxides, alkaline cyanide, alkaline sulfide, as well as nitrate, carbonate, chromate, acetate and ammonia solution and so on, may use the carbon steel at room temperature. In addition, anic solvents such as hydrocarbons, alcohols, amines, aldehydes and ketones, can also be used to make carbon steel containers. Tap water, river water, sea water, distilled water so the corrosion of carbon steel, and water dissolved oxygen, flow, PH value, temperature, bacteria, etc. is different, they are very different。 the same time, with the steel surface state related. Ⅲ、 lowalloy steel corrosion resistance Corrosion resistance of lowalloy steel is a lowalloy steel is an important branch of the class. Add the main alloying elements to improve the corrosion of steel in different environments in the corrosion resistance. However, for this purpose to add a small amount of multialloy steel is often the same time, the mechanical properties and process performance of the larger impacts, both beneficial side also has a negative side, which to the corrosion of low alloy steel and production increased the difficulties. Corrosion is still a developing lowalloy steel in the steel type, there is no uniform classification. Now more mature and effective corrosion resistance of lowalloy steel are: (1) The atmospheric corrosionresistant lowalloy steel. (2) sulfuric acid dew point corrosion resistant lowalloy steel. (3) seawater corrosionresistant lowalloy steel. (4) milk sulfide corrosion of lowalloy steel. (5) Other corrosion resistant lowalloy steel. In other corrosion resistant lowalloy steel, there are hightemperature, high pressure, hydrogen, nitrogen, and corrosionresistant lowalloy steel, etc. bittern. China39。 s highstrength lowalloy steel with the corrosion of lowalloy steel has been around 30 years of history, and achieved considerable results. (A) Atmospheric corrosionresistant lowalloy steel Without the protection of ordinary carbon steel under the conditions of exposure to the atmosphere, the corrosion, the corrosion rate and the relationship between environmental factors greatly. Atmospheric corrosion is usually a typical environment, there are three types: the rural atmosphere, industrial atmosphere and ocean atmosphere. Among them, rural countryside of atmospheric corrosion of mild steel。 and industrial air vary widely, affecting different。 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。 s countries are trying to add a variety of small amount of the steel alloying elements to enhance the atmospheric corrosion resistant steel their ability to develop a group of lowalloy steel resistant to atmospheric corrosion. Corrosion of carbon steel in the atmosphere originally developed rapidly, when the rust layer formed, the average corrosion rate will be slowed. Because of this rust porous layer and its adhesion is poor, coverage is not uniform, unable to withstand wind and rain and the role of alternating wet and dry at any time by peeling off, so that corrosion, localized corrosion, especially the further development . Lowalloy steel corrosion in the atmosphere, mainly to improve the structure of the rust layer and improve the extent of the rust layer and the dense steel adhesion, enhanced the role of newly isolated with the air. Over the past decade, the United States ambassador to the successful development of rust color with an artistic lowalloy steel, not paint directly exposed to the use of a building with a beautiful tan. alloy elements on corrosion resistance of steels in the impact of atmospheric Atmospheric corrosionresistant lowalloy steel, the effective alloying elements are mainly copper, phosphorus, chromium, nickel, etc., these elements are enriched in the surface of steel and formed amorphous layer increases in the atmospheric environment in the steel corrosion resistance. Cu: Copper atmospheric corrosion resistant steel has an obvious effect of a large number of domestic and international experimental study and confirmed。