Corossion of behavior boronized AISI 1010 dual phase steels

Boriding is a thermochemical surface hardening process that especially provides high surface hardness and corrosion resistance. In spite of paramount properties, especially in our country industry, boriding is not enough used. It is known that losing material reaches high level with corrosion. Structural steels which are cheaper than variety of other steels are widely produced in our country and the world. Important advantages from the point of view economics and manufacturing technique can be provided by forming dual phase microstructure by heat treatments in structural steels. The dual phase steels which have ferrite and martensite phases in their microstructures have high strength due to martensite and high ductility because of ferrite phases.In this study, corrosion behaviors of boronized and non-boronized dual-phase steel were investigated with electrochemical methods (Tafel extrapolation and linear polarization methods) in a 3.5wt.% NaCl solution. Dual phase steels is boronized with the dust of commercial Ekabor-2 in 900 oC temperture for two hours. Boride layer of surface morphology of the optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were determined. Microstructure analyses show that the boride layer on the dual-phase steel surface had a flat and saw smooth morphology. It was detected by X-ray diffraction (XRD) analysis that the boride layer contained FeB and Fe2B phases. The amount of martensite increases with an increase in the intercritical ivannealing temperature. Both the amount of martensite and the morphology of the phase constituents have an influence on the corrosion behavior of dual-phase steel. A higher corrosion tendency was observed with an increased amount of martensite. The corrosion resistance of boronized dual-Phase steel is higher compared with that of dual-Phase steel.Key Words: : Dual-phase steel, Boronizing, Ferrite, Martensite, Corrosion.