Study on the Perspective of Mechanical Properties and Corrosion Behaviour of Stainless Steel, Plain and TMT Rebars

Abstract

In the present research, the effects of various alloying elements and microstructural constituents on the mechanical properties and corrosion behaviour have been studied for four different rebars. The microstructures of stainless steel and plain rebar primarily reveal equiaxed ferrite grains and ferrite-pearlite microstructures, respectively, with no evidence of transition zone, whereas tempered martensite at the outer rim, followed by a narrow bainitic transition zone with an internal core of ferrite-pearlite, has been observed for the thermomechanically treated (TMT) rebars. The hardness profiles obtained from this study display maximum hardness at the periphery, which decreases gradually towards the centre, thereby providing the classical U-shaped hardness profile for TMT rebars. The tensile test results confirm that stainless steel rebar exhibits the highest combination of strength (≈755 MPa) and ductility (≈27%). It has been witnessed that in Tafel plots, the corrosion rate increases for all the experimental rebars in 1% HCl solution, which is well expected because the acid solutions generally possess a higher corrosive environment than seawater (3.5% NaCl) due to their acidic nature and lower pH values. However, all the experimental results obtained from Tafel and Nyquist plots correlate well for both 1% HCl and 3.5% NaCl solutions.

Evaluation of corrosion behaviour of turmeric-coated AZ51 alloy in simulated body fluid for biomedical applications

“…Furthermore, the sample coated for 48 h shows the lowest corrosion rate, thereby having maximum corrosion resistance. It is a well-established fact that a lower value of corrosion rate shows a higher corrosion resistance behaviour of the sample [44]. According to the Faraday's law, by utilising the corrosion current density, the corrosion rate has been computed as follows [44–47].…”

“…It is a well-established fact that a lower value of corrosion rate shows a higher corrosion resistance behaviour of the sample [44]. According to the Faraday's law, by utilising the corrosion current density, the corrosion rate has been computed as follows [44–47]. where i corr is the corrosion current density in (A/cm 2 ), F is the Faraday's constant (96,500 C/mol), m depicts molar mass of magnesium in (g/mol), z is the number of electrons transferred for each metal atom and ρ is the density of the metal, here magnesium, in (g/cm 3 ).…”

“…The results of the same data have been summarised in Table 7. This is a wellestablished fact that the lower the corrosion rate of a sample more enhanced is the corrosion resistance of the sample [42,44].…”

“…Furthermore, the sample coated for 48 h shows the lowest corrosion rate, thereby having maximum corrosion resistance. It is a well-established fact that a lower value of corrosion rate shows a higher corrosion resistance behaviour of the sample [44]. According to the Faraday's law, by utilising the corrosion current density, the corrosion rate has been computed as follows [44][45][46][47].…”

“…Furthermore, a higher value of R ct reveals a higher value of corrosion resistance for the sample [46,50]. Additionally, the arc diameter in the Nyquist diagrams can be considered as Rs, and the arc diameter reduction reveals a decrease in R p values [44,46]. It can be observed from both Figure 4(a) and Table 5 that the R p value and R c values show higher values for the DC-48 sample which was well expected and correlated with the other studies performed in the current research, followed by DC-96, DC-24 and UC sample, respectively.…”