Closed Type Cross Wedge Rolling Forming Shaft Parts And Its End Quality Research

At present，almost all of the domestic and foreign scholars who study on Cross wedge rollingis work on the order rolling (also known as "open rolling"), as to the research of closed rolling israre, this paper will focus on the closed type cross wedge rolling forming shaft parts and its endquality research. This article applied finite element software DEFORM-3D numerical simulationcalculation, first of all, through the closed type cross wedge rolling stress and strain analysis tounderstand the metal flow characteristics of the closed type cross wedge rolling; Again through theanalysis of strain field, displacement field achieved the generate mechanism of the concavity of theclosed type cross wedge rolling, and made comparison with open type cross wedge rollingtechnique, the results show that the concavity length of the rolled piece of the closed type crosswedge rolling process was reduced by48.35%than the open type cross wedge rolling technique;Finally calculated by finite element achieved the influence rule of the forming angle α, broadeningangle β, reduction of area ψ and billet diameter D four process parameters on the end quality of theclosed type cross wedge rolling.In order to further control the concavity, improve the quality of rolled piece end, based on theclosed type cross wedge rolling process, it design three different schemes to control concavity,respectively based on block wedge closed type cross wedge rolling process, close and open jointcross wedge rolling process and change the end shape. In this paper, a detailed explanation of thethree schemes, including the design of the mould and eng shape design of the billet. The researchresults show that the concavity length of the based on block wedge closed type cross wedge rollingtechnique was reduced by71.6%than the general closed type cross wedge rolling technique; Theend of the rolled pieces of close and open joint cross wedge rolling process tend to be flat, achievednon-remnants and precise forming; The concavity size of the rolled pieces decreases with theincrease of The circular arc angle θ, when the billet end design in a semicircle as90°, the end ofrolled pieces of concave heart obviously decreases, and just40.67%of the original length ofconcavity. Finally combined with experimental verification for billet shape scheme, the resultsconsistent with simulation results.The research results in this paper are help to further improve the quality of the end of therolled piece, increase the material utilization of cross wedge rolling process, and also rich thediversity of cross wedge rolling process, which is useful for the further development andapplication of cross wedge rolling theory foundation.