Best practices to assess the corrosive properties of stainless steel

What are the Best Practices to Assess the Corrosive Properties of Stainless Steel?

Stainless Steel

Due to its, supposed, non-corrosive properties, stainless steel is gradually replacing other metals. Especially in industrial applications where the shelf life of the machine is more important than its cost, manufacturers are replacing other alloys with stainless steel. Other domestic applications, like utensils, faucets, door knobs, cabinet handles, metal furniture and many other things are now available in stainless steel. It’s an alloy and has approximate 10.5% chromium. There is a complete range of grades available in stainless steel, which is achieved by adding various alloy elements. In accordance with the alloy percentage, the chemical and physical properties change.

Corrosion resistance is a vital parameter that defines the grade and quality of the steel. Like other metals, stainless steels respond when subjected to the salt laden environment. Salt spray tester simulates an accelerated corrosive environment, which however is exaggerated than normal working conditions. But to test the efficiency of the product, you need do the performance analysis, when it is exposed to conditions that may lead to failure easily. The salt solution used for this analysis has 5% of NaCl, which is more than sea water. As per the ASTM B117, the temperature is maintained somewhere between 35°C to 47°C. The test cycle in continuous without opening the canopy of the chamber, as this may lead to fog dissipation.

Facts about corrosive testing of stainless steel

Operators often try to correlate the results of the test with the behaviour of the sample with real working conditions. Here, certain corrections need to be done. First of all, the operator has to understand the conditions simulated by salt spray tester are the harsh conditions and there is very less possibility that product would ever get exposed to such condition.

Indeed, this is an accelerated test, the operator can assume that if there is minimalistic corrosion in the production after 128 hours of the test, means the product would definitely survive the real working conditions. The operator can definitely use this process for the grading of stainless steel. To get the best results out of it, the texture of the surface should exactly be the replica of the final product. The results produced by salt spray test are faster than field tests, due to accelerated ageing process.

Presto group offers multiple models of salt spray chamber or corrosion chamber. From basic to high-end models, this feature loaded machine is perfect for different types of metal testing under different temperature ranges.