Study on corrosion damage characterization and tensile strength evaluation for locally corroded bridge steel via metal magnetic memory method

Abstract

Corrosion is a severe threat to the load-bearing capacity of steel members in bridges. Metal magnetic memory (MMM) is considered a potential method for detecting corrosion damage. In this paper, the SMFL signals HSFy on 27 Q345qD specimens with local corrosion were measured, and then the tensile tests for all specimens were performed. The results show that the crest-trough spacing on the gradient K curves can locate the position and range of corroded region accurately. The difference HSF,my between the maximum and minimum of HSFy signals and the crest-trough difference Kc-t of the gradient K curve can be utilized for the comprehensive characterization of the corrosion damage degree. Finally, the correlation between HSF,my and strength degradation degree η was established to realize the quantitative evaluation of tensile strength. This research serves as a base for corrosion damage characterization and tensile strength evaluation for bridge steel members via the MMM.