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The increasing use of polymer products in transportation and almost all sectors is a distinctive sign of the current decade. On-site repair of defects along the spatial path are important advantages of a portable welding and repair system. The current article presented an in-house developed pneumatically powered portable set-up and tool for defect repair based on friction stir welding (FSW). The suggested tool can be used for welding polymer products such as car bumpers, motorboats, and polymer vessels. Further, acrylonitrile butadiene styrene (ABS) polymer specimens were joined by FSW and friction stir spot welding (FSSW), and the maximum temperature was monitored. FSW process parameters: rotational speed and traversing velocity, and FSSW parameter: rotational speed and dwell time, were varied, and the design of experiment-based investigations was carried out. Response surface method (RSM) and analysis of variance (ANOVA) were used to analyse the results. The acceptable results were obtained for rotational speed of less than or equal to 1100 rpm and welding velocity lower than 6.5 mm/min (for FSW). Good quality welds were obtained for dwell time equal to or higher than 25 s (for FSSW). The preferred temperature for a good quality weld was found to be 105°C in both processes. [ABSTRACT FROM AUTHOR]

Friction Stir Welding (FSW) has revolutionized modern manufacturing with its advantages, such as minimal heat-affected zones and improved material properties. Accurate torque prediction in FSW is crucial for weld quality, process efficiency, and energy conservation. Many researchers achieved models for torque based on experimental research, yet the models were limited to a specific type of material. In recent years, the use of machine learning techniques has increased in industry in general and in welding in particular. In this study, a machine learning model was prepared based on artificial neural networks, and Shapley-Additive Explanations were used to predict the rotational torque from 287 experiments that had been conducted in several previous studies. The achieved model has remarkable predictive performance, with an R-squared of 99.53% and low errors (MAE, MAPE, and RMSE). Moreover, a machine learning polynomial regression was examined for comparisons. A parametric importance analysis revealed that rotational speed, plate thickness, and tilt angle significantly affect torque predictions, while the rest of the variables had minimal importance. [ABSTRACT FROM AUTHOR]

Reinforced concrete RC is a versatile and durable building material widely used in construction. This study investigated the impact of PVC-coated steel wire mesh layers on the compressive strength of RC. Seven cube specimens (70 × 70×70 mm) with varying numbers of PVC-coated layers were tested after a 28-day curing period. Results showed that specimens with two layers of PVC coating exhibited the highest ultimate compression stress and breaking force, indicating a significant 38% increase in compressive strength compared to those without PVC coating. The findings suggest that PVC-coated steel wire mesh provides a sustainable and costeffective method for reinforcing RC structures. By mechanically enhancing these structures, their overall mechanical properties can be improved. This research highlights the potential of PVC-coated steel wire mesh as an effective reinforcement technique, offering practical solutions for strengthening concrete structures. [ABSTRACT FROM AUTHOR]

Steel pipelines are commonly used in the petroleum industry, where high strength and durability values are required. In oil installations, the problems of corrosion, especially with crude oil, appear clearly and dramatically in dealing with API 5L series. Improving the corrosion protection and mechanical properties is a genius goal for steel manufacturers, and the heat treatment processes are familiar in this field. In this study, experimental investigations were executed to find the heat treatment influence on the corrosion rate, microstructure, and mechanical properties behavior of API 5L X60 pipeline steel in the presence of three different environments: seawater, freshwater, and crude oil. Two austenitizing temperatures, 900°C and 800°C, were prepared, followed by quenching at 600°C, 450°C, and 300°C, respectively, where the corrosion rate was estimated by the mean weight loss method. In this study, more than 60% of the corrosion rate in both seawater and freshwater was improved at 900 ºC, austenitizing tempered at 300ºC, for the selected pipeline specimens, while only 22% reduction was achieved in crude oil. Different microstructure phases appeared in the heat-treated specimens such as tempered martensitic at 300°C and fine-grained ferrite with polygonal ferrite at 600°C. The microhardness values decreased with increasing the tempering temperatures, while impact toughness values increased with tempering temperature increasing from 300°C until it reached 450°C and then returned to decrease again in 600°C. [ABSTRACT FROM AUTHOR]