Proposed Methodology for Inter-Comparison of Steel Rebar Properties from Different Manufacturing Sources

Abstract

We propose a new method for checking steel quality and repeatability in microstructure using a combination of X-Ray diffraction (XRD) and Raman Spectral data analysis methodology¹. Here, we discuss the case of steel rebars. We consider 23 different brands of steel rebars from across India. We did an inter-comparison of their elemental chemical composition using X-ray fluorescence (XRF) data, observed their crystalline properties using X-Ray diffraction (XRD) patterns, peak full width at half maximum (FWHM) values. The wet etched micrographs of their cross-sections were inter-compared to show the extent of variation. Even though the XRD data of these samples are similar, the wet etched micrographs along with the Raman spectral data varied a lot from brand to brand. Effects of halides, oxygen, nitrogen impurities on its long-term corrosion and degradation of rebars is also discussed. It is suggested that better convergence of Raman spectral data for all brands of steel rebars along with their FWHM values will replicate similar microstructural images across all brands and will thus ensure better formulation of uniform quality standards across all brands and ensure higher longevity of related civil engineering structures, irrespective of the brand.