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Go to Editorial ManagerAISI 4330 Low-alloy steel is good material for advanced application because of its properties including strength and longevity. However, performance may be modified with heat treatment procedures, include quenching and tempering. These processes can create residual stresses and retained austenite (RA), which have an effect on the metal's application. these factors influence fatigue life, dimensional stability, and fracture toughness of engineered components. uncontrolled residual stresses can reduce fatigue strength by up to 30%, while optimal retained austenite content (e.g., 5-10%) can enhance damage tolerance. This study focuses on residual stresses and retained austenite measurement in AISI 4330 low-alloy steel after heat treatment. including experimental and simulation methods. The review summarizes many scientific studies published between 2019 and 2024 and shows some main challenges. One challenge is the difference between experimental results (for example, from X-ray diffraction (XRD) and neutron (diffraction) and simulation results (especially using ANSYS software). Another challenge is that different methods for measuring retained austenite can give different results, which can change how we understand the steel's properties. The review also explains new progress in modeling heat treatment. This includes adding phase transformation models to finite element simulations. Future efforts should combine multiscale simulation, characterization, and machine learning to achieve predictive control over these properties in manufacturing.
The current approach to cooling water treatment is to use a multi – component inhibitors. Cooling water formulations containing mixtures of inhibitors usually offer better and increased protection to ferrous metals than similar concentrations of either of the individual components. Such mixtures are synergistic in their action .But; the synergistic effects between nitrites, molybdates and inorganic phosphate were not investigated until recently. A weight loss technique was used to investigate such mixture and to optimize the concentrations of the components in the blend.Consequently; an efficient and effective blend was developed as a corrosion inhibitor for carbon steel in aerated Al–Daura refinery re-circulating cooling water in the pH range 6.75 to 7.25. The preferred concentrations of components in the multi- component inhibitor blend (as ppm ) were: (SN + SM): SHMP = 800: 20 with SN: SM weight ratio =3:2.The reduction in corrosion rate was 97.6 % .
The enormous volume of crude oil that needs to be transported results from the growing demand for petroleum. One of the most practical ways to move crude oil is via pipelines. This paper's primary objective is to examine the effects of sulphur, one of the components of crude oil, on welded pipes (API 5L X60, X46, and X42 pipes as well as ASTM A106 pipes). It also aims to show how sulphur content influences different kinds of pipes separately from the other important components of crude oil. The sulphur content of crude oil is determined using the TR-TCXRF equipment. The corrosion rates of welded pipes in four immersion solutions (Different percentages of sulphur content) were computed using weight loss. The samples' corrosion characteristics were assessed morphologically using an optical microscope (OM), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Petroleum welded pipelines' mechanical qualities and resistance to corrosion are significantly impacted by sulphur; an increase in sulphur concentration resulted in a higher rate of corrosion and a decrease in mechanical properties. Among all the welded pipes utilized in the paper, the API 5L X60 welded pipe had the highest corrosion rate, whereas X46 welded pipe was more corrosion-resistant than X46 and X42 in API 5L-type pipes and ASTM A106 pipe.
This paper presents a pressure drop analysis in perforated vertical wellbores for different perforation parameters. The effect of the density of the perforations (number of perforation), the phase angle of the perforations, the diameter of the perforation and the flow rate of the crude oil from the perforations on the pressure drop and the productivity index of the perforated vertical wellbores were studied. The analysis of the vertical wellbore was performed numerically using ANSYS FLUENT 15.0 software. Three dimensional, steady-states, turbulent and incompressible fluid flow is assumed during the numerical solution of the governing equations. The results of this study show that, increased perforation density of the perforated vertical wellbore caused an increase in pressure drop, and also, decreased productivity index due to increasing the friction losses. Friction pressure drop has a significant effect on crude oil flow into the wellbore. When the main velocity is 1.5 m/s and the inlet velocity from the perforations is 2 m/s, the friction pressure drop is about 66 % and the acceleration pressure is approximately 34 % of the total pressure drop.
A numerical simulation of the effect evaluation of heat loss and temperature distribution along the wellbore is performed, for two models, the first is an open hole (without perforation) and the other is a perforated vertical wellbore. In this study, the Computational Fluid Dynamics (CFD) software code ANSYS FLUENT 15.0 has been used, for simulate a model of 3-D turbulent flow with stander k-ϵ model. The results of this show that, increasing the heat losses leads to an increase in the temperature gradient, while the temperature gradient decreases with increasing inlet main velocity. Also, the temperature of the produced crude oil decreases with increasing the length of the wellbore.
In this research, the effect of seawater environments and surface roughness on uniform corrosion rate of carbon steel (A516 grade 65) was studied depending on the experimental work and artificial neural network modeling. The experimental work involves chemical composition, samples machining, roughness measurements (for carbon steel specimens), conductivity and salinity measurements (for seawater), and uniform corrosion test. Weight loss technique was employed in determining the uniform corrosion rate in carbon steel material. Also, artificial neural network (ANN) model was built to predict the values of uniform corrosion rate (mpy) at different values of conductivity, salinity for seawater and roughness factor for carbon steel depending on the experimental results which were used train and test the ANN. The results obtained of uniform corrosion rate by ANN predictions are shown to be agreed well against experimental values. i.e. correlation coefficient, R=0.9974
Impact energy prediction of thermal aged cast stainless steel from impact test was studied using artificial neural network (ANN) modeling. Impact energy data for specimens from eleven cast stainless steel alloys at different aging times and temperatures, were used to evaluate possible artificial neural network architecture for prediction impact energy. These data are taken from Argonne National Laboratories (ANL) in USA that involved impact test results of cast stainless steel after aging between 200 and 400oC for up to 30000 hour. The ANN model exhibited excellent comparison with experimental results of ANL i.e. correlation coefficient (R=0.9451) and mean square error (MSE=1.2*10-5). Since a large number of variables were used during training the ANN model, a reliable and useful predictor for impact energy in thermal aged cast stainless steel was provided.
Failures in the steam tubes of boiler furnaces in Najebia power plant was studied experimentally. Visual examination, mechanical tests, microscopic test and chemical analyses were performed. Visual examination showed the types of failure in the tubes. Tensile and hardness tests were performed to estimate the variation in the mechanical properties of the tubes metal and compared with the new tubes. Microscopic test for the failed tubes used to recognize the difference in the microstructure to the metal of the tubes. Chemical analyses involved chemical composition of the tubes metal, river and feed water analyses, water treatment, fuel analyses and analysis of deposits and oxides on the external and internal sides. Overheating and wall thinning of the tubes resulted from oxygen escaping to the inner side of these tubes, and presence of deposits and oxides on the external and internal sides which led to failure was studied extensively. Engineering remedies were also given to confine the problem and to prevent it in future.