Abstract
The aim of this paper is to evaluate the influence of small variations in chemical composition on the corrosion resistance and mechanical properties of low-manganese and medium manganese high strength steels. Six different steels with manganese content varying from 1.5 to 4.0 wt.% and aluminium from 0.008 to 6.5 wt.% were subjected to the analysis. The other subjects for evaluation included the effect of aluminium as a replacement for silicon, niobium microalloying and the effect of heat treatment. The effect of non-metallic inclusions on localized corrosion initiation and propagation was also documented. Using potentiodynamic testing, exposure testing, tensile and impact testing, it was found that the improvement in corrosion resistance associated with increasing aluminium content is accompanied by a significant deterioration of the mechanical properties. Niobium microalloying and heat treatment was found to have no quantifiable impact on the anti-corrosion properties. The effect of aluminium content proved to be superior to the effect of nonmetallic inclusions in terms of determining the overall corrosion resistance of the experimental steels.
Highlights
Over the last two decades there has been a trend towards replacing conventional mild steels with high strength steels (HSS) and advanced high strength steels (AHSS)
The following findings can be stated: The numerical results from potentiodynamic testing did not show any considerable differences in the corrosion resistances of the experimental steels, which exhibit better corrosion properties, especially corrosion rate, than the earlier high alloyed manganese-aluminium steel grades
The improved corrosion resistance of the steels studied here can be attributed to relatively low manganese content (1.5 to 4 wt.%), which decreased the significance of soluble corrosion products of manganese
Summary
Over the last two decades there has been a trend towards replacing conventional mild steels with high strength steels (HSS) and advanced high strength steels (AHSS). The main object focus of HSS/AHSS research and development is on achieving an optimum strength-weight ratio. Many researchers have concentrated on the effect of alloying elements on the mechanical properties which are essential in terms of the processability and safety of the final product [1,2]. One of the main alloying elements in AHSS, ensures the stabilization of retained austenite and enables the use of the TRIP/TWIP effect during cold plastic deformation. Earlier grades of AHSS with manganese content around 20 wt.% exhibited elongation over 50% and strength up to 1000 MPa. the current trend in AHSS development is to avoid any uneconomical alloying concepts, i.e., keeping the manganese content below 10 wt.% while maintaining the exceptional mechanical properties of the steel [3,4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
