The direct loss caused by corrosion to metal materials is huge. Some people count about 100 million tons of metal that are scrapped and scrapped in the world each year, accounting for 20%to 40%of the annual output. And with the process of industrialization, the problem of corrosion is becoming more and more serious. In 1949, the US corrosion consumption (material consumption and corrosion) was $ 5 billion, reaching 70 billion US dollars in 1975, as high as 168 billion U.S. dollars in 1985. Compared with 1949, it increased compared More than 80 times. It is estimated that the worlds annual steel equipment that is scrapped due to corrosion is equivalent to 30%of the annual output. Obviously, the destruction of metal components is far more valuable than the value of metal materials; the economic loss caused by corrosive countries in developed countries accounts for about 2%to 4%of the total production value of the country. Energy; my countrys economic losses caused by corrosion at least 20 billion yuan each year. The huge harm of corrosion is not only reflected in economic losses, it will also bring heavy personnel casualties, environmental pollution, waste of resources, hindering the development of new technologies, and promoting the loss of natural resources.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
salt mist corrosion background and mechanism7wlTextile Testing Instruments, Testing Equipment Manufacturer
Corrosion is damage or deterioration caused by the material or its performance under the action of the environment. Most corrosion occurs in the atmospheric environment, and the atmosphere contains corrosive ingredients and corrosion factors such as oxygen, humidity, temperature changes, and pollutants.7wlTextile Testing Instruments, Testing Equipment Manufacturer
Salt mist corrosion is a common and most destructive atmospheric corrosion. Among them, salt fog refers to the atmosphere of chloride, and its main corrosion is sodium chloride. The corrosion of salt fog on the surface of the metal material is caused by electrochemical reactions of the oxidation layer and protective layer and internal metal on the metal surface of chloride ions. At the same time, chloride ions contain a certain hydrophobic energy, which is easily adsorbed on the pores on the metal surface, the cracks are crowded and replaced the oxygen in the chlorine layer, turning insoluble oxides into soluble chloride, making the passivation surface become lively On the surface, it causes a bad reaction to the product.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
anode: metal lost electrons and turned into metal cations, and entered the solution in the form of hydrated ions, while leaving considerable electrons in metal.7wlTextile Testing Instruments, Testing Equipment Manufacturer
ME+NH2O RARR; ME2+Middot; NH2O+2E-7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
Catalur: The remaining electrons left in the cathode metal are removed from oxygen, restored and restored and restored Absorbing electrons becomes hydroxide ions.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
O2+NH2O+4E- RARR; 4oh-7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
Electrolytic solution: sodium chloride ion and chloride ions, partial chloride ions, metal ions and metal ions and metal ions and metal ions and metal ions and metal ions and metal ions and metal ions and metal ions and metal ions and metal ions Hydroxygenocytes react into metal corrosion.7wlTextile Testing Instruments, Testing Equipment Manufacturer
2ME2 ++ 2CL-+2oh- RARR; MECL2 Middot; Me (OH) 27wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
salt fog corrosion hazard7wlTextile Testing Instruments, Testing Equipment Manufacturer
1) Salt and fog corrosion will destroy the metal protective layer, make it lose decorative, reduce the mechanical strength;7wlTextile Testing Instruments, Testing Equipment Manufacturer
2) Some electronic components and electrical lines are interrupted due to corrosion. Especially in a vibrating environment, it is particularly serious;7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
3) When the salt fog landed on the surface of the insulator, it will reduce the surface resistance; after the insulator absorbs the salt solution, its volume resistance will reduce the number of four quantitative levels of magnitude magnitudes. ;7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
4) The activity site of mechanical parts or motion components due to the generation of corrosion, increased friction and even causing the motion parts to be stuck.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
Metal material salt fog corrosion test test7wlTextile Testing Instruments, Testing Equipment Manufacturer
salt fog test is divided into natural environment exposure test and artificial acceleration simulation environment test, the latter is the latter is the latter, which is the latter. The salt fog test box is used to make a salt -fog environment in its volume space to evaluate the salt -resistant corrosion performance quality of the product.7wlTextile Testing Instruments, Testing Equipment Manufacturer
Compared with the natural environment, the salt concentration of chloride in its salt and mist environment can be several times or dozens of times of salt and mist content of the average natural environment, which greatly improves the speed of corrosion. Tests, the results of the results are also greatly shortened. If a sample of a product is tested in a natural exposure environment, it may take 1 year after its corrosion, and test under the conditions of artificial simulation of salt fog, as long as 24 hours, you can get similar results. However, the artificial acceleration simulation test is still different from the natural environment, so it cannot be replaced.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
Test method7wlTextile Testing Instruments, Testing Equipment Manufacturer
Neutral salt fog test (NSS test)7wlTextile Testing Instruments, Testing Equipment Manufacturer
At present, the most widely used field of acceleration corrosion tests. It uses 5%sodium chloride saline solution, and the pH value of the solution is adjusted in a neutral range (6-7) as a solution for spray. The test temperature is taken at 35 deg; C, and the sedimentation rate of the salt mist is required between 1-2ml/80cm middot; h.7wlTextile Testing Instruments, Testing Equipment Manufacturer
The acetate mogo test (ASS test)7wlTextile Testing Instruments, Testing Equipment Manufacturer
developed on the basis of a neutral salt fog test. It adds some methamphetamine to 5%sodium chloride solution to reduce the pH value of the solution to about 3, the solution becomes acidic, and the final salt mist also changes from neutral salt mist to acidic. Its corrosion speed is about 3 times faster than the NSS test.7wlTextile Testing Instruments, Testing Equipment Manufacturer
Copper salt accelerated acetate fog test (LRHS-663P-LY)7wlTextile Testing Instruments, Testing Equipment Manufacturer
is a newly developed rapid salt fog corrosion test in foreign countries. At 50 deg; C, a small amount of copper salt mdash; copper chloride was added to the salt solution, which ly induced corrosion. Its corrosion speed is about 8 times the NSS test.7wlTextile Testing Instruments, Testing Equipment Manufacturer
Salt Misty Misty Test7wlTextile Testing Instruments, Testing Equipment Manufacturer
YesA comprehensive salt fog test, which is actually a neutral salt fog test plus constant damp heat test. It is mainly used for the entire machine product of the cavity. Through the infiltration of the moisture environment, the corrosion of salt fog is not only produced on the surface of the product, but also inside the product. It alternate the product under the environment of salt and fog and damp heat, and finally evaluates whether the electrical performance and mechanical properties of the entire machine product have changed.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
Results Determine7wlTextile Testing Instruments, Testing Equipment Manufacturer
The purpose of the salt fog test is to evaluate the salt -resistant corrosion quality of the product or metal material, and the results of the salt fog test results The judgment is the verdict of the quality of the product. Its judgment results are correct and reasonable, and it is the key to correctly measure the quality of products or metal anti -salt fog corrosion. The method of judging the results of the salt fog test results include: rating judgment, weighing judgment method, corrosion judgment method, and corrosion data statistical analysis method.7wlTextile Testing Instruments, Testing Equipment Manufacturer
1) Rating judgment method: The percentage of the ratio of the corrosion area to the total area is divided into several levels according to a certain method, and a certain level is used as the basis for the judgment of the qualified judgment, which is suitable for tablet sample evaluation.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
2) Weight judgment method: By changing the weight of the sample before and after the corrosion test, calculate the weight (or weight increase) of the corrosion loss to the sample corrosion quality, which is suitable for some metal Evaluation of corrosion resistance.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
3) Corrosion judgment method: It is a qualitative judgment method. It is determined by whether the product generates corrosion after the salt fog corrosion test. Most of the general product standards adopt this method.7wlTextile Testing Instruments, Testing Equipment Manufacturer
7wlTextile Testing Instruments, Testing Equipment Manufacturer
4) Corrosion data statistical analysis method: It is mainly used for analysis and statistical corrosion, not the quality judgment of a specific product. More about:7wlTextile Testing Instruments, Testing Equipment Manufacturer
Salt and Mist aging test box7wlTextile Testing Instruments, Testing Equipment Manufacturer
