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This study aims to investigate chip formation and surface generation during the precision turning of stainless steel 316L samples. A Finite Element Method (FEM) was used to simulate the chipping process of the stainless steel but with only a restricted number of process parameters. A set of turning tests was carried out using tungsten carbide tools under similar cutting conditions to validate the results obtained from the FEM for the chipping process and at the same time to experimentally examine the generated surface roughness. These results helped in the analysis and understanding the chip formation process and the surface generation phenomena during the cutting process, especially on micro scale. Good agreement between experiments and FEM results was found, which confirmed that the cutting process was accurately simulated by the FEM and allowed the identification of the optimum process parameters to ensure high performance. Results obtained from the simulation revealed that, an applied feed equals to 0.75 of edge radius of new cutting tool is the optimal cutting conditions for stainless steel 316L. Moreover, the experimental results demonstrated that in contrast to conventional turning processes, a nonlinear relationship was found between the feed rate and obtainable surface roughness, with a minimum surface roughness obtained when the feed rate laid between 0.75 and 1.25 times the original cutting edge radius, for new and worn tools, respectively.

This study presents a comprehensive evaluation of Equal Channel Angular Pressing (ECAP) processing on the structural evolution and mechanical properties of AA2xxx aluminum alloy. Finite element analysis (FE) was used to study the deformation behavior of the AA2xxx billets during processing in addition investigate the strain homogeneity in the longitudinal and transverse direction. Billets of AA2011 aluminum alloy were processed successfully through ECAP up to 4-passes with rotating the sample 90° along its longitudinal axis in the same direction after each pass (route Bc) at 150 °C. The microstructural evolution and crystallographic texture were analyzed using the electron back-scatter diffraction (EBSD) and optical microscopy (OM). An evaluation of the hardness and tensile properties was presented and correlated with the EBSD findings and FE simulations. The FE analysis results were in good agreement with the experimental finding and microstructural evolution. Processing through 4-passes produced an ultrafine-grained structure (UFG) and a recrystallized fine grain dominated the structure coupled with a geometric grain subdivision which indicated by grain refining and very high density of substructures. This reduction in grain size was coupled with an enhancement in the hardness, tensile strength by 66.6%, and 52%, respectively compared to the as-annealed counterpart. Processing through 1-pass and 2-passes resulted in a strong texture with significant rotation for the texture components whereas 4-passes processing led to losing the symmetry of the texture with significant reduction in the texture intensity.

In this work, the aqueous Lawsonia inermis extract (LI) is investigated as an economic and green deterioration inhibitive formula for steel alloy 4130 in 3.5 wt.% NaCl solutions. The water-based extraction process is considered as one of the cheapest techniques for preparation of active ingredients of natural products. These ingredients play an important role in corrosion mitigation of steel alloy 4130 in saline media. This extract was subjected to three different parameters: inhibitor concentration, rotation speed, and temperature in 3.5 wt.% NaCl solutions. The electrochemical techniques are used to perceive the corrosion behavior, and the obtained results were dedicated to theoretical explorations to assess the features of corrosion inhibition and the adsorption over the steel substrate in 3.5 wt.% NaCl solutions. Affording to the electrochemical techniques of LI showed very promising results against corrosion depending on the inhibitor concentrations. The inhibition efficiency of LI was additionally appraised at three diverse temperatures, and the results disclosed that the inhibition efficiency is decreased. Additionally, the theoretical aspects illuminated that the main active ingredients of LI have a proclivity to coagulate on the steel substrates allowing these areas to paradigm a protecting layer on the steel surfaces. This behavior is in provision of investigational results. Statistical studies were used to examine the consequence of chief constraints (i.e., inhibitor concentration, temperature, and rotation speed) on the inhibition efficiency and the rate of corrosion of steel alloy 4130. The inhibitive effect of LI in contradiction of the corrosion of steel alloy 4130 surfaces is considered by resources of DFT/6-31G(d) calculations. The quantum chemical parameters interrelated to the inhibition efficiency are considered.