The influence factors of stamping stainless steel surface passivation membrane

Stamping stainless steel in the process of actual use, there are many causes can make stainless steel passivation film is destroyed, the transformation of the passivity of stainless steel to living condition. To lower the corrosion resistance of stainless steel. ( 1) The chloride ion. Great harm of chloride ion of stainless steel. Should be strictly controlled in the process of passivation passivation solution, the chloride ion content in passivation with chemical materials used for the chloride ion are limited. Make the passivation liquid water and clean water also have strict quality request for the chloride ion, to ensure that the passivation products not cleave the chloride ion, in order to avoid future trouble. ( 2) Surface cleanliness. For stainless steel alloy, the lower the surface roughness, surface more smooth, foreign body harder weng, ministries, the lower the risk of local corrosion. Therefore, should be used as finish of stainless steel. In addition, the stainless steel surface cleanliness is very important also, passivation after the final cleaning should be done carefully, because the residual acid promotes the cathodic reaction, break the membrane layer, so that the activation of stainless steel, corrosion resistant performance drastically reduced. ( 3) Using the environment medium. Stainless steel passivation film belongs to the thermodynamics on inhibition of metastable structures mouth the protection efficiency related to environmental medium. In use should be regular cleaning, remove harmful substances long-term private attached on the surface. Especially in chloride environment, avoid long time breasts are attached to the surface and chloride ion concentration in the water mouth, such as stainless steel utensils used in food industry, every time after contact with the food, all want to wash, so as to avoid the chloride ion, damage the passivation film. Such as containers and equipment used for dairy products, dairy products contain chloride has damage to the passive film, such as all dairy products for a long time, can lead to capacity and equipment corrosion perforation, regular cleaning, so to restore the passivation film. ( 4) The internal factors of stainless steel. Content of the martensite content of chromium and nickel in stainless steel had a great influence on the passivation performance of stainless steel. Low nickel content, passivation performance is low. Martensite stainless steel passivation membrane performance on the passivation performance of the austenitic stainless steel is better than a: metal stamping parts how new products into the market