Study Of Corrosion Mechanism And Property Of Metal Parts Of Refrigerator

The metal materials widely used for Refrigerator inner decoration and appearance are stainless steel, aluminum alloy, galvanized steel, etc. These materials would be corroded affected by environmental factors, such as acid, alkali, salt, temperature and humidity. Even if the corrosion is not necessarily change the strength of the material, but they can cause damage for the appearance, it will also affect people using the refrigerator. This requires materials using for fridge to have high corrosion resistance.Main purpose of this paper is determining various metals corrosion mechanism, corrosion speed and corresponding relation with time, through the analysis of metals corrosion products; On this basis, using appropriate accelerated corrosion test to simulate the actual condition, getting the level of corrosion resistance which the different metals normal can reach, and confirming the choice of metal materials. In this paper, the material we study is 430 stainless steel,3003 aluminum alloy, galvanized steel, both provided by Midea refrigerator co., LTD. Corrosion environment is divided into two type:One is the inner decoration corrosion environment, main corrosion condition is acid,alkali and alkaline which contact role from food; The other is mainly atmospheric corrosion environment. We use solution immersion test, including acid、 alkali、sodium chloride solution to simulate the working condition of the refrigerator inner decoration environment. Through the experiment: In a weak acid environment, corrosion resistance of 430 stainless steel and aluminum alloy is very good, galvanized material is serious; In a weak alkaline environment: stainless steel does not corrode, corrosion occur in the aluminum alloy and galvanized zinc. Although the zinc’s corrosion products can protect substrate material, its mechanical strength is low. Three kinds of materials in salt solution all corroded, but stainless steel keeps the best appearance.For atmospheric corrosion of appearance, we design two acceleration spectrum: one is CORR test which the main corrosion factors are Cl", Cu2+ and temperature and humidity, another is Cyclic acidified salt fog testing which the main factor of corrosion are H+, Cl-, temperature and humidity. In CORR Testing: the relationship between the corrosion weightlessness and the corrosion time of 3003 aluminum alloy and 430 stainless steel is in power relations, corrosion mechanism is pitting, corrosion products are Fe3O4 and Al (OH) 3 respectively; Relationship between corrosion weightlessness and time of Galvanized steel is in a straight line, corrosion mechanism is pitting, corrosion products is Zn(OH) 2. Corrosion mechanism of the 430、3003、galvanized steel is the same as natural environment corrosion, and the dynamic relationship、 corrosion products、the corrosion morphology are same. In addition, Grey relational analysis method is used to study the correlation between two kinds of accelerated corrosion and atmospheric corrosion in typical region. Through the analysis, the relevance between CORR testing and atmospheric testing is more than that between Cyclic acidified Testing and atmospheric testing. Galvanized material is more suitable for Cyclic acidified salt fog testing. According to equation between corrosion time of indoor and outdoor corrosion, we can calculate the acceleration in CORR testing and Cyclic acidified salt fog testing.