Scientists develop mathematical model to select optimal welding parameters

SUSU

An international team of scientists is working to improve the quality of welding seams when welding weathering steel.

South Ural State University (USUS) scientists have identified the parameters that influence the quality of welding, and the interrelation of characteristics of the technological process and the quality characteristics of welding seams. Based on the data collected during the study, a mathematical model for selecting optimal parameters was built. The study was published in The International Journal of Advanced Manufacturing Technology.

Weathering steel belongs to the class of high-strength low-alloy steels with a low carbon content and a small amount of other alloying elements (aluminum, titanium, copper, etc.). Senior Research Fellow of the SUSU Department of Welding Production Technology and Equipment, Ph.D. in the field of Mechanical Engineering, Associate Professor of the School of Mechanical Engineering of Linyi University, China, Zhao Dawei is working on methods to improve the quality of welding of weathering steel.

"This type of steel has an excellent combination of strength, ductility, formability and weldability," said Zhao Dawei. "Moreover, this material can provide improved atmospheric corrosion resistance. Weathering steels are used in the construction of oil pipelines, bridges, ships, and buildings. The quality of welding of A606 weathering steel is very important in the production of critical welding structures such as boilers, tanks and oil pipelines.

SUSU scientists examined different combinations of welding parameters and then evaluated the quality of welding seams.

"We examined the influence of certain welding variables (welding speed, welding current and wire feed speed) on the geometry of weld bead and its tensile properties," said Dawei. "Within the framework of the study, the characteristics of the microstructure in various technological parameters of welding were identified, and the correlation between the parameters of welding and its quality indicators was analyzed. After calculating the optimal welding parameters, we performed validation to obtain high-quality welding seams. With optimal welding parameters, the quality of welding seams increases.

Different welding parameters, such as voltage, welding speed, welding current, shielding gas, wire feed speed, type of wire, and its diameter, influence the physical and mechanical properties of welding seams. Incorrect welding parameters can lead to unavoidable defects, which adversely affect the quality of welding.

This project was launched in 2021. According to the previous research work, welding heat input has a strong influence on the quality of welding and is determined by the parameters of the welding process.