民用飞机腐蚀防护与控制.ppt

腐蚀防护与控制 腐蚀防护与控制CORROSION PREVENT AND CONTROL 飞机防腐基础知识CORROSION PREVENT BASIC KNOWLEDGE FOR AIRCRAFT 飞机防腐的一般处理方法 BASIC CORROSION TREATMENT TECHNIQUES 飞机防腐工艺理论及提高 CORROSION PREVENT THEORIES AND FURTHER 飞机防腐基础知识CORROSION PREVENT BASIC KNOWLEDGE FOR AIRCRAFT The purpose of this chapter is to provide information that will help maintenance personnel prevent, control, identify, and treat various types of corrosion. 本章的目的是帮助维修人员在工作中防止、控制、区分以及处理各类腐蚀。 目录CONTENTS 1、腐蚀CORROSION 2、影响腐蚀的因素FACTORS INFLUENCING CORROSION 3、常见腐蚀剂COMMON CORROSIVE AGENTS 4、腐蚀类型TYPES OF CORROSION 5、常用材料的防腐措施CORROSION PROTECTION MEASURES FOR BASIC MATERIALS 6、腐蚀的预防CORROSION PREVENTIVE MAINTENANCE 7、飞机的目视检查指南VISUAL CORROSION INSPECTION GUIDE FOR AIRCRAFT 8、腐蚀去除相关规定CORROSION REMOVAL PROCEDURES 9、基本的腐蚀去除工艺BASIC CORROSION REMOVAL TECHNIQUES 1、腐蚀CORROSION Corrosion is a natural occurrence that attacks metal by chemical or electrochemical action and converts it back to a metallic compound 腐蚀是通过化学或电化学方式使金属转变为其金属化合物的一种自然反应。 电化学腐蚀ELECTROCHEMICAL CORROSION All metals and alloys are electrically active and have a specific electrical potential. The constituents in an alloy also have specific electrical potentials which are generally different from each other. Exposure of the alloy surface to a conductive corrosive medium (electrolyte) causes the more active metal to become anodic and the less active metal to become cathodic, thereby establishing local cells. The greater the difference in electrical potential between the two metals, the greater will be the severity of a corrosion, if the proper conditions are allowed to develop. The electrochemical corrosion is responsible for most forms of corrosion on aircraft structure and components. 所有金属和合金都有电化学活泼性，有一定的电位。合金中的不同成份之间电位也不相同。一旦合金表面接触到导电的，或腐蚀性的介质（电解液）会使较活泼的金属变为阳极，不活泼金属变为阴极，形成微电池。如果存在合适的条件，那么，两种金属间的电位相差越大，腐蚀就越剧烈。 电化学腐蚀是飞机结构和部件的主要腐蚀形式。 电化学腐蚀原理 电化学腐蚀发生的四个条件：Four conditions must exist before electrochemical corrosion can occur： （1）A met