Simulation And Experimental Of Hot Flanging Forming Of Three-Limb Tubes

Multi-pass pipe especially T-tee in the petroleum, chemical,aerospace,aviation and other fields have been widely used in the era of the rapid development of the industry.The quality requirements of the tee along with the increase of applications increased,so the traditional manufacturing process has been difficult to achieve the desired of the quality requirements.Therefore, we explore a new type of tee process-cold flanging process.Cold flanging is a machining process with a certain size of the prefabricated holes at room temperature. Compared with the traditional casting,sheet metal and other tee production process, using cold flanging tee physical process to produce better performance,better flow properties pipe lines and process more material savings.The research of the tee cold flanging process has just started in domestic,there are still many problems, the key issues of the forming process have be studied in the paper.As a part of a tee connection pipe is welded to the other member,which requires as much as possible during processing to improve tee nozzle manifolds flatness。 Flanging process, the preformed hole size,the shape of the punch, flange fillet may affect the flatness of the nozzle manifolds, the maximum impact is pre-hole,so the shape of the preformed hole is optimized.In this paper,the mathematical model, finite element simulation, optimization design and experimental methods were used to study the cold flanging process preformed hole shape and size.Mathematical model to calculate the size of pre-hole tee was studied,calculated based on pre-formed hole size of the flat flange,two prefabricated hole size calculation method is proposed:one is the theory of law, such as line length;another theory is the equal-area method. The mathematical model of pre-calculated pore shape and size based on the tow methods,and the establishment of appropriate solver.In order to verify the accuracy of the two mathematical models, finite element simulation method is to use.Through the study of cold flanging process we design the mold, Using the software of UG4.0to design the three-dimensional modeling diagram of the mold;To calculate pre-hole shape and size,the mathematical model has been used,and build the three-dimensional shape of the blank;Using finite element analysis software for finite element analysis and outcome.After a comparative analysis,the pre-hole of the equal length theoretical is better, but there are also some errors.In order to improve the quality of the tee flanging,we optimized the prefabricated holes on the shape and size.By calculating anywhere flange height difference between the ideal height we can get pre-hole size and the size of the difference between the ideal and current and get the ideal pre-hole profile. We can obtain the ideal shape and size of pre-hole through multiple optimization.In order to determine the reliability of the results of numerical analysis and design optimization, the process of the cold flanging has been experimental studied. This paper analyzes the results of three different shapes of the prefabricated hole flanging.That is the standard pre-hole fittings, optimized prefabricated hole fittings and0.95times optimized pre-hole fittings. The results of flanging of optimized prefabricated hole are very satisfactory and the quality has greatly improved,but the pipe with the proportionally reduced prefabricated hole flange failure(crack),so prefabricated hole size has been optimized to achieve optimal.