A drawing-flaring process of metal bushing ring without welding seam for plate heat exchanger

A metal bushing ring is an important part of the plate heat exchanger, which plays the role of sealing, and the welding seam formed in the current forming processes shortens the life of the plate heat exchanger. A drawing-flaring process of a metal bushing ring without a welding seam is proposed, which includes deep drawing and multi-flaring processes, and the latter is the process that matters. Considering the uneven thickness after deep drawing, an analytical model is established to predict the stress and strain states, thickness distribution, flaring ratio, and driving force in multi-flaring. The whole process FE model is also established, and its reliability is validated through an experiment. Deformation characteristics, thickness distribution, flaring ratio, and driving force are studied by comparing the results of the experiment, finite element analysis (FEA), and theoretical analysis. The buckling phenomenon easily occurs in 90° flaring, so improvements are proposed to enhance the stability, which can avoid the defects. The results prove that the drawing-flaring process is feasible, and the analytical model is reliable.