Development of new methods of manufacturing of large-diameter double-seam pipes

A contemporary metallurgical plant consists of numerous auxiliary and primary shops, and they require continuous economic investment. Saving on physical resources, raw materals, etc., as well as of reduction of the metal consumption rate, production optimization and flexibility is an important issue for metallurgical companies in the context of economic instability in the industry. This article describes new methods of manufacturing expandable electric resistance welded pipes out of two sheets (double-seam pipes). Using modern methods of engineering analysis based on the finite element method (FEM), the authors evaluated the possibilities of implementing new methods of manufacturing large-diameter double-seam pipes, and also selected such molding process modes that allow obtaining such products that comply with customer's requirements. The article describes results of test surveys, reproducibility evaluation of the results obtained with CAE-systems, and experimental shop operation results. The new mathematical models of manufacturing pipe blanks using basic molding operations are highly reproducible and may be used to calculate pipes of other dimensions. Use of MSC Software (specialized software) to simulate the new mathematical models helps to evaluate new process modes and various production techniques without risks or financial losses. The proposed new methods of manufacturing large-diameter double-seam pipes (sheet molding out of two halves and semi-cylinder molding) helped to increase production yield and flexibility and positively affected cost-effectiveness (due to fewer expenses on sheet blanks). The authors confirmed efficiency of these methods and proved in the field (experimental lot production) that they may be reasonably used.