This study focuses on investigating the effect of Terminalia chebula Ritz. extract (TCE) for corrosion inhibition of Al in phosphoric acid (H₃PO₄) using potentiodynamic polarization (PDP) technique. In this study, the effect of concentration of TCE extract, the concentration of H₃PO₄ acid medium, and temperature (T) was investigated on the corrosion current density (i_corr) and inhibition efficiency (IE). The TCE was characterized by FTIR analysis, and the adsorption of TCE was justified with the help of kinetic, thermodynamic, adsorption isotherm parameters. The surface morphology study was done using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXS), and atomic force microscopy (AFM). The study also focuses on identifying the optimum process parameters for obtaining the maximum IE by applying the response surface methodology (RSM) and desirability function approach. The maximum IE of 83.24% was achieved at a temperature of 30 ℃, the concentration of TCE extract of 500 ppm, and H₃PO₄ acid concentration of 0.5 M. Regression analysis, Pareto chart, normal chart, main effect, and interaction effect plots are employed to acquire an in-depth understanding of process variables on IE. The IE obtained from the experiments and the predicted model is in a close match and a high value of the coefficient of determination (R² = 99.98%) displays that the generated model was able to estimate the IE accurately from the selected process variables.

The proposed review demonstrates the effect of the surface modification process, specifically, deep rolling, on the material surface/near-surface properties of commercial steels. The present research examines the various process parameters involved in deep rolling and their effects on the material properties of AISI 1040 steel. Key parameters such as the rolling force, feed rate, number of passes, and roller geometry are analyzed in detail, considering their influence on residual stress distribution, surface hardness, and microstructural alterations. Additionally, the impact of deep rolling on the fatigue life, wear resistance, and corrosion behavior of AISI 1040 steel is discussed. Engineering components manufactured by AISI 1040 steel can perform better and last longer when deep rolling treatments are optimized with an understanding of how process variables and material responses interact. This review provides critical insights for researchers and practitioners interested in harnessing deep rolling techniques to enhance the mechanical strength and durability of steel components across diverse industrial settings. In summary, the valuable insights provided by this review pave the way for continued advancements in deep rolling techniques, ultimately contributing to the development of more durable, reliable, and high-performance steel components in diverse industrial applications. The establishment of generalized standardizations for the deep rolling process proves unfeasible because of the multitude of controlling parameters and their intricate interactions. Thus, specific optimization studies tailored to the material of interest are imperative for process standardization. The published literature on the characterization of surface and subsurface properties of deep-rolled AISI 1040 steel, as well as process parameter optimization, remains limited. Additionally, numerical, analytical, and statistical studies and the role of ANN are limited compared with experimental work on the deep rolling process.

The adsorption of pectin and corrosion inhibition of dual-phase AISI1040 steel with ferrite–martensite and ferrite–bainite structure in 0.5 M sulphuric acid (H₂SO₄) solution have been investigated using the weightloss method. This work investigates the adsorption mechanism and quantum chemical calculations of pectin. For a specific set of parameters such as immersion time and concentration of inhibitor, the maximum inhibition efficiency of 83.36% is observed. The inhibition efficiency increased with pectin concentration and decreased with immersion time at 30 ℃. The results from the statistical analysis show that the concentration of inhibitor is having the highest influence with a 43.87% contribution on the inhibition efficiency. The adsorption study revealed that the Langmuir adsorption isotherm gave the best-fit results out of all the isotherms studied. Theoretical studies based on density functional theory supported experimental observations. From the results, it was also observed that lower weight loss and better inhibition efficiency are achieved in the case of ferrite–bainite when compared to the ferrite–martensite structure. Surface characterization confirmed corrosion and inhibition on the surface of the metal as the surface became uneven when exposed to a corrosive medium and smooth when immersed in the inhibited solution.

Dual-phase steels provide an excellent combination of strength and ductility, as well as improved energy absorption and anti-corrosion protection properties. This research aims at evaluating the microstructure and corrosion behaviour of EN8 steel under different heat treatment temperatures in 0.5 M sulphuric acid solution (H₂SO₄) using the EIS, potentiodynamic polarization, and gravimetric method (weight-loss method). Austenitizing is performed at 973 K, 1023 K, 1063 K, and 1173 K for 2 h followed by quenching in water to form a ferrite–martensite (F–M) dual-phase structure. From the results, it is seen that the corrosion rate increased with different heat treatment conditions depending on the change in the phase when immersed in 0.5 M H₂SO₄ at the temperature of 303 K, 313 K, 323 K, and 333 K. This work investigates the energy of activation, enthalpy, and entropy of activation. For dual-phase steel containing ferrite and martensite, the corrosion behaviour depends on the amount of martensite and ferrite. As the austenitization temperature increases from 1023 to 1173 K, the amount of martensite increases. This is reflected in the increase of micro galvanic corrosion cells in the region between the ferrite and martensite phases, which acts as active corrosion centres. The normalized specimen showed greater corrosion resistance compared to the water-quenched specimen at 1173 K. This is due to the presence of lower carbon content for normalized dual-phase steel containing ferrite–pearlite phase than the ferrite–martensite phase present in specimen austenitized at 1173 K. Surface characterization and XRD confirmed the corrosion behaviour of the specimens under investigation.

The purpose of this study is to investigate the corrosion behavior of the ferrite-bainite phase of AISI1040 steel and its corrosion inhibition using pectin in 0.5 M sulphuric acid medium. The corrosion study was conducted through weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) measurements. The study was conducted within the temperature range of 313–343 K and immersion time of 1 h— 7 h. The inhibition performance of pectin has boosted with an increase in the concentration of pectin and decreased with the temperature and time of exposure. From the weight loss study, the highest inhibition efficiency of 85% was achieved at 5.0 g/L at 1 h of exposure at 40 °C. The activation, thermodynamic, and adsorption isotherm were adapted for the experimental results. The energy and enthalpy of activation emphasized on energy barrier for the corrosion process. The entropy of activation values is negative, indicating the association of molecules. The physical adsorption of pectin on the metal surface was confirmed by the free energy of adsorption (close to-20kj mol⁻¹). The enthalpy of adsorption indicated the exothermic process and, arrangement of the molecules on the surface of the metal expressed by the entropy of adsorption. The optimum efficiency of 74.9% is achieved for the addition of 5.0 g/L of pectin at 313 K by the EIS technique. Surface analyses involving a scanning electron microscope and atomic force microscopy were carried out to understand the nature of the surface in the presence and absence of pectin.