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• Dynamic loaded tooth contact analysis (DLTCA) for computing entrainment speed. • Accurate solution to elastohydrodynamic lubrication (EHL) governing equation. • Discrete convolution and fast Fourier transformation (DC-FFT) for flank elastic deformation. • A separation flow method for iteration of EHL governing equation. • Accurate entrainment effect-based EHL forecasting model for hypoid gears. In full consideration of time-varying meshing performance and oil film characteristics, entrainment effect on elastohydrodynamic lubrication (EHL) is developed for establishing accurate forecasting model of the complex hypoid gears. Firstly, dynamic loaded tooth contact analysis (DLTCA) is employed to determine the meshing interface kinematics, load distribution and entrainment speed under dynamic load condition. Then, entrainment speed is introduced into the EHL governing equation and accurate forecasting model is established. With accurate discretization of EHL governing equation, discrete convolution and fast Fourier transformation (DC-FFT) method is employed to compute the flank elastic deformation. Finally, a hypoid gear set in automotive industrial application is exercised to verify entrainment effect on EHL assessment in the proposed model. [ABSTRACT FROM AUTHOR]

The corrosion behavior of austenitic stainless steel after low-temperature liquid oxy-nitriding (LON) was investigated by exposing in H 2 S/CO 2 -saturated liquid and vapor environments up to 720 h at 60 °C. The corrosion rates before and after LON were compared by the weightlessness method, and the microstructure as well as the corrosion scales were characterized using surface analysis methods. The results indicated that the composite S-phase layer with the outer Fe 3 O 4 layer and the inner nitrogen-rich sublayer could improve the corrosion performance in H 2 S/CO 2 -saturated environment. The base material (BM) suffered local corrosion first, which then transformed into uniform corrosion. As a comparison, The LON sample, covered with a thin corrosion product layer, indicated slight local corrosion. The excellent corrosion resistance of the S-phase should be attributed to the blocking effect of the continuous Fe 3 O 4 film as well as the suppression of the atomic mobility by the nitrogen-containing supersaturated solid solution. • The difference in the corrosion behavior of austenitic stainless steel in the vapor and liquid phases is analyzed. • In the H 2 S/CO 2 -saturated liquid/vapor phase, the corrosion rate of the LON sample is 93.1% lower than that of the BM. • The nitrogen atoms in the S-phase can increase the local pH value and accelerate the passivation in acidic environments. • The continuous Fe 3 O 4 layer can effectively block offensive ions. • Supersaturated nitrogen could suppress the atomic mobility thereby reducing the dissolution of metal atoms. [ABSTRACT FROM AUTHOR]

The study focused on investigating the phenomenon of stress corrosion cracking induced by H 2 S, while also examining the influence of low-temperature oxy-nitriding (LTON) surface modification on the diffusion behavior of hydrogen atoms through electrochemical hydrogen charging experiments. Following the hydrogen charging process, the concentration of diffusible hydrogen in the base material (BM) was measured at 5.41 ppm (ppm), which reduced to 1.10 ppm after implementing LTON treatment. Clearly, the surface-modified layer effectively hindered the diffusion of hydrogen atoms within the steel substrate. In the case of BM specimens exposed to H 2 S stress corrosion, the duration of exposure significantly impacted the formation of corrosion products. Additionally, the externally applied tensile stress played a pivotal role in the cracking behavior, as increasing stress levels led to the emergence of deformation bands outside the C-ring and ultimately initiated cracks at the base of the pits. Notably, H 2 S stress corrosion pits accumulated oxides and sulfides. Excessive hydrogen supersaturation potentially induced localized plastic deformation. Furthermore, due to the presence of sulfide ions, hydrogen atoms could not recombine to form hydrogen molecules, resulting in an accumulation of hydrogen atoms on the steel surface. The diffusion of hydrogen atoms within the steel material strongly influenced the initiation and propagation of stress corrosion cracking. Importantly, the surface modification layer established by LTON treatment exhibited remarkable capability in enhancing the steel material's resistance against H 2 S-induced stress corrosion. This was achieved by effectively preventing acidic medium attack and impeding the penetration of hydrogen atoms. • In comparison to 304 stainless steel, the electrochemical hydrogen charging of the LTON modified layer reduced the hydrogen content in the sample by 80%. • The H 2 S stress corrosion cracking behavior of austenitic stainless steels was investigated to reveal the transformation mechanism of cracks under different corrosion times and stresses. • The composite S-phase layer formed after LTON treatment can significantly improve the stress corrosion performance of stainless steel and prevent the penetration of hydrogen atoms. [ABSTRACT FROM AUTHOR]

As a mature technology, electroless Ni–P alloy coating is widely applied in the protection of chemical equipment and pipelines owing to its excellent corrosion resistance, but its application and long-term service evaluation in the field of high-sulfur oil and gas are rare. Therefore, the time-dependent corrosion behavior of Ni–P coating, which was plated on the L360 steel surface, was investigated in a saturated H 2 S medium by the method of surface analysis. The results indicate that Ni–P coating with a thickness of about 52.6 μm could significantly reduce the corrosion rate compared with uncoated pipeline steel. This is related to the structure of the dense, protective film on the surface. The uncoated pipeline steel suffered local corrosion during the immersion process, and then it developed into uniform corrosion with the formation of a large number of corrosion products. In comparison, Ni–P coatings corroded relatively mildly with only a thin corroded layer. However, during prolonged corrosion testing, the corrosive medium penetrated the coating/substrate interface at inherent defects, leading to severe local corrosion of the substrate. • Corrosion behavior of electroless Ni–P coating in saturated H 2 S solution was evaluated during long-term immersion. • The types of corrosion products formed on Ni–P coating were analyzed at various times. • Ni–P coating can resist H 2 S attack for a short time. • After long-term immersion, the failure of the coating is related to its inherent defects. [ABSTRACT FROM AUTHOR]

• Corrosion behaviors of S-phase and austenitic stainless steel in H 2 S/CO 2 /Cl− media were evaluated after long-term immersion. • The types and effects of corrosion products were analyzed at various times. • The Fe 3 O 4 layer can effectively block corrosive ions. • The presence of the S-phase layer reduced the corrosion rate of AISI 304 steel by 89.8 %. S-phase was introduced on stainless steel surface by low-temperature liquid oxy-nitriding and its influence on the corrosion behavior has been explored through surface analysis and weight-loss method. The results indicated that the S-phase layer can significantly improve the corrosion resistance of austenitic stainless steels in H 2 S/CO 2 /Cl− simulated solutions, which was proved by lower corrosion rate, surface, and cross-sectional topography after corrosion. This improvement can be attributed to the fact that the Fe 3 O 4 layer blocking the sulfur-containing medium and the consumption of H+ by the active nitrogen atoms, making it difficult for the corrosive medium to penetrate the steel. [ABSTRACT FROM AUTHOR]

• A sharing model of charging piles in a noncooperative game context is proposed. • A hierarchical scheduling model of EVs is proposed, which coordinates charging stations and shared charging piles to charge EVs. Electric vehicle (EV) will not only effectively promote the popularization of charging facilities, but also reduce the dependence on fuel vehicles. However, large-scale charging behaviours of EVs will bring new challenges to match between charging facilities and EVs. Due to the limited capacity of the centralized charging stations, it is difficult to meet the charging demands of EVs in certain areas, especially during the peak load periods. To solve the insufficiency of charging capacity caused by the mismatch between charging stations and EV charging loads, this paper proposes a hierarchical scheduling model of EVs considering shared charging piles. The upper scheduling model determines the charging time of EVs based on the charging demands. The lower scheduling model coordinates charging stations and shared charging piles to determine the charging locations of EVs. The sharing scheme of private charging piles is determined by sharing capacity model based on the generalized Nash game. The quantum particle swarm algorithm with the dynamic feedback mechanism is adopted for a better convergence of the solving process of the hierarchical scheduling model. The simulation results on IEEE 33-node system are conducted to validate the effectiveness of the proposed model and solution algorithm, which show the extensive potential applications in EV scheduling. [ABSTRACT FROM AUTHOR]

The effects of low-temperature oxy-nitriding (LTON) treatment on the liquid lead-bismuth eutectic (LBE) corrosion behaviors of 316 L ASS were investigated in the stagnant liquid LBE under vacuum at 823 K. Results show that the untreated samples were severely selective leaching in contact with liquid LBE. LTON treatment produced an outer porous Fe-Cr spinel film and inner S phase layer on the sample surface, which transformed into a thicker spinel film containing γ low-N and a region distributed with CrN precipitates after liquid LBE corrosion. This was mainly attributed to the oxidation and decomposition of S phase and inward diffusion of the interstitials, owing to S phase is a metastable phase and is easier to be oxidized than matrix at elevated temperatures. This inspired us that improving the ability to form protective oxide film for materials was maybe a good method to mitigate the liquid LBE corrosion. [Display omitted] [ABSTRACT FROM AUTHOR]

An effective and biodegradable Stevioside from Stevia leaf was evaluated as a potential pickling inhibitor in combination with the Zn2+ cation for C1020 carbon steel (CCS). Considering its naturally occurring, cheap and environmentally safe properties, Stevioside has the potential to be widely used to inhibit the CCS corrosion in HCl solutions. The corrosion inhibition performances of Stevioside and Stevioside –Zn2+ were studied with the use of weight loss test, electrochemical techniques, and surface analysis methods. The results demonstrated an incorporation of Zn2+ component into the Stevioside layer can evidently improve the uniformity and anti-corrosion properties (i.e. , 76.59 % versus 95.68 %). The optimal molar ratio of Stevioside /Zn2+ was found to be 1:2, and the highest inhibition efficiency was 95.68 % evidenced by electrochemical test. Polarization diagrams revealed that the Stevioside and Stevioside –Zn2+ behaved as mixed type inhibitors and mainly inhibited the anodic process. The surface morphology by SEM, SECM and XPS confirmed the effectiveness of the inhibitor. Molecular dynamics simulations disclosed that the inhibitor retard the CCS corrosion during the descaling process through the mechanism donor-acceptor interaction. [ABSTRACT FROM AUTHOR]