Evaluation of Corrosion, Mechanical Properties and Hydrogen Embrittlement of Casing Pipe Steels with Different Microstructure

In the research, the corrosion and mechanical properties, as well as susceptibility to hydrogen embrittlement, of two casing pipe steels were investigated in order to assess their serviceability in corrosive and hydrogenating environments under operation in oil and gas wells. Two carbon steels with different microstructures were tested: the medium carbon steel (MCS) with bainitic microstructure and the medium-high carbon steel (MHCS) with ferrite–pearlite microstructure. The results showed that the corrosion resistance of the MHCS in CO2-containing acid chloride solution, simulating formation water, was significantly lower than that of the MCS, which was associated with microstructure features. The higher strength MCS with the dispersed microstructure was less susceptible to hydrogen embrittlement under preliminary electrolytic hydrogenation than the lower strength MHCS with the coarse-grained microstructure. To estimate the embrittlement of steels, the method of the FEM load simulation of the specimens with cracks was used. The constitutive relations of the true stress–strain of the tested steels were defined. The stress and strain dependences in the crack tip were calculated. It was found that the MHCS was characterized by the lower plasticity on the stage of the neck formation of the specimen and the lower fracture toughness than the other one. The obtained results demonstrating the limitations of the usage of casing pipes made of the MHCS with the coarse-grained ferrite/pearlite microstructure in corrosive and hydrogenating environments were discussed.

The Proton Pump Inhibitor (Lansoprazole Drug) As a Corrosion Inhibitor for High Carbon Steel in Hydrochloric Acid Solution

The proton pump inhibitor lansoprazole (PPIL) drug is examined as corrosion inhibitor for high carbon steel (HCS) dipped in 1.0M HCl. The study was conducted utilizing ac impedance spectroscopy (EIS), Mass loss (Ml), polarization tests, and surface checks were utilized to illustrate the importance of this PPIL extract to the prevent corrosion process for HCS. The influence of temperature and concentration of PPIL on the efficiency of inhibition were tested. The corrosion mechanism occurs, when the PPIL extract molecules block the active center in the electrode surface. The inhibition efficiency (%IF) of HCS occurs by the adsorption procedure and HCS is subject to the adsorption of Langmuir. Polarization curves showed that PPIL drug is a mixed- type inhibitor that retards the dissolution of HCS. IF % was deliberated with altering in the concentration of PPIL various temperature of the medium. From the outcome data we get that the good agreement in the all methods.

Microstructure Evolution of the Carbon Steels During Surface Severe Plastic Deformation

The review is devoted to the state-of-the-art views on the microstructure evolution in structural and tool carbon steels during the surface severe plastic deformation (SPD). The main focus is on the effects of the nanocrystallization in the near-surface area of the low-carbon steel (C 0.05–0.2%), medium-carbon steel (C 0.35–0.65%), and high-carbon steel (C 1.0–1.5%). It is reviewed the following advanced surface SPD methods for the metal surfaces in recent years: an ultrasonic impact peening (UIP), high-frequency impact peening (HFIP), air blast shot peening (ABSP), surface mechanical attrition treatment (SMAT), and laser shock peening (LSP). Microstructure evolution before and after SPD is studied by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effects of the SPD parameters on the nanocrystalline modification of such main phase components of the carbon steels as ferrite, pearlite, and cementite are analysed. The atomic mechanism of the nanocrystallization is presented. The strain-hardening effect induced by SPD is demonstrated by the data of the near-surface microhardness profiles.

Parameters of Porosity and Compressive Strength-Based Optimization on Reinforced Aluminium from the Recycled Waste Automobile Frames

Automobile industries were ready to recycle the waste old parts as well as the damaged parts of the old vehicles as much as possible. This study mainly focused on the recycling of the waste and damaged aluminium frames of the automobile bodies. These aluminium-based frames only collected the metal matrix composite created by reinforcement of 3% silicon carbide (SiC) and 3% high carbon steel. The stir casting method is chosen to make the composites. Optimization is done by Taguchi ANOVA technique. Three input parameters such as stir speed, time of squeeze, and the temperature of the preheating were considered. The outputs such as compressive strength and porosity were experimentally measured with the combination of nine (L9) experimental trails. The measured experimental results were analyzed and optimized with the help of Taguchi technique with different plots for clear identification. The optimized parameters based on low porosity and high compressive strength were recommended for conclusion.

Study on Static Strain Aging Kinetics of High-Carbon Steel Wires and Its Impact on High-Strength Steel Cords

Under quasi-static loading, an irregular failure mode of high-strength thin carbon steel cords were observed after low-temperature thermal aging. Character and kinetics of damage in such wire ropes highly depend on the plastic elongation of the steel wires, which is significantly modified by the strain aging effect. In this paper, the static strain aging effect on heavily drawn high-carbon steel wires and their cords is experimentally studied in the 80–200 °C temperature range. The kinetics of the aging process is studied in detail. Experimental data are fit by the Johnson–Mehl–Avrami–Kolmogorov (JMAK) kinetic model. The temperature dependence of the static strain aging process is given by means of the Arrhenius equation. The associated JMAK exponents, the apparent activation energy and the pre-exponential constant are determined. Quantitative analysis of the affected strength and strain parameters is given, and based on this, the macroscopic failure mechanism is fundamentally explained.

Experimental Investigation on the Effect of Different Micro-Geometries on Cutting Edge and Wiper Edge on Surface Roughness and Forces in Face Milling

The significance of the micro-geometries on the cutting edge is known from numerous studies conducted in the past. However, the effect of micro-geometry on the wiper facet (also called the wiper edge) is not known. Hence, this paper investigates the effect of different micro-geometries with a focus on geometry variation on the wiper edge of a milling insert on surface roughness and forces in face milling of SAE1070 high-carbon steel. Milling inserts with sharp, rounded, chamfered edges and their combinations were manufactured on the cutting edge and wiper edge for the study. Critical surface quality parameters such as the average surface roughness (Ra), mean depth of surface roughness (Rz), and force components such as radial force (Fx), cutting force (Fy), and axial force (Fz) were evaluated. Metal cutting tests were performed at three different cutting speeds and three different feed rates to study the influence of cutting parameters and the effect of edge geometries on surface roughness. The results were correlated with the force values to understand the machining dynamics. Finite element analysis was performed to evaluate the high and low-stress zones on the insert, workpiece, and chip to understand the metal cutting mechanism of different micro-geometries. The novel finding from the study is that having identical micro-geometries on the cutting and wiper edge is the preferred combination, whereas dissimilar micro-geometries result in reduced surface quality, increased forces, and high stress on the workpiece and chip.