Effect of corrosion on mechanical properties of coupons taken from high strength steel tubes

Utilization of high strength steel (HSS) tubes has recently increased as an alternative to conventional structural mild steel (MS) tubes because of its unique characteristics such as high energy absorption, and weight saving. Despite its superior features, susceptibility of HSS to corrosion is an issue that needs to be considered in engineering design. If not accounted for, corrosion could lead to strength loss, safety issues, contamination, etc. This paper reports the results of a comparative study conducted on different grades of HSS tensile coupons extracted from tubular sections exposed to various simulated corrosive environments. Grades 1200 MPa and 800 MPa HSS tubular sections have been used in the experimental program. For the sake of comparison, the coupons taken from Grade 350 MPa mild steel tubes have also been tested under the same condition. The influence of corrosive environments on mechanical properties is studied by defining tensile strength and elongation reduction indices. The experimental test results demonstrated that the grade of steel tubular section plays a significant role in its performance under corrosive environment. The outcomes of this research have the potential to be incorporated in codes of practice for rational design and analysis of high-strength steel tubular structures subject to corrosion.