GB/T 41756-2022 English PDF (GBT41756-2022)

This document presents three methods for evaluating the atmospheric corrosion resistance of low-alloy steels. Method One is the prediction method based on short-term corrosion data of steel. Method Two is the prediction method based on the chemical composition of steel. Method Three is the prediction method based on environmental factors and steel chemical composition. Method One in this document applies to the use of existing short-term atmospheric corrosion data in different environments for specific grades of low alloy steel. Evaluate its long-term corrosion damage. Method Two is suitable for evaluating the relative corrosion resistance of low alloy steel based on the atmospheric corrosion resistance index (I). Method Three is suitable for estimating the corrosion loss of low alloy steel at different times in different environments. NOTE: These three methods are calculated based on the experimental data of flat bare steel exposed specimens. The actual atmospheric corrosion rate is much higher when the low alloy steel is kept wet for a long time or is severely attacked by some salts or other corrosive chemicals.