Research on the ovality of hollow shafts in cross wedge rolling with mandrel

Abstract

The trend towards lightweight construction has increased the use of hollow shafts. Cross wedge rolling (CWR) is a competitive near-net-shape forming process that can reduce costs and improve quality in the production of hollow shafts. The ovality of workpiece is the most important issue for making hollow shafts by cross wedge rolling with mandrel, and the process parameters are the main influence factors. The relationships between the process parameters and ovality were investigated by analyzing the influence of the helical and circular contact area between the tool and workpiece on the metal flow using the finite element method. Through the definition of ovality coefficient, a method for predicting the ovality of workpiece and choosing the process parameters was established. The simulation results were verified via rolling experiments and used to develop a process of cross wedge rolling the axle sleeves of truck with good forming quality. This work can provide a theoretical guidance for the tools design and production application of cross wedge rolling hollow shafts with mandrel.

A rotary compression test for determining the critical value of the Cockcroft–Latham criterion for R260 steel

“…The change in diameter is accompanied by an increase in the specimen's length – in this way the specimen fills the entire width of the channel. The rest of the material fits into the channel as the specimen is ovalized, a phenomenon that typically occurs in cross wedge rolling of hollow or solid workpieces subject to cracking (Yang and Hu, 2016). A small amount of material also flows outside the channel.…”

Research and industrialization of near-net rolling technology used in shaft parts

“…However, this has several disadvantages, such as huge equipment tonnage, complex processes, and low material utilization. The USTB team has researched stable rolling conditions, flattening deformation [51], microstructure evolution [52], and ellipse generation [53][54][55] of hollow pieces formed by CWR with mandrel. The team has successfully originated the method of CWR hollow axle sleeve of a heavy-duty truck with mandrel [56].…”

Experimental Research for the Establishment of the Optimal Forging and Heat Treatment Technical Parameters for Special Purpose Forged Semi-Finishes

“…Since studying the absolute plastic properties of non-metallic inclusions is difficult to carry out, most experimental research sought to study the ability to deform non-metallic inclusions in the metal matrix, using relative indices comparing the plastic properties of non-metallic inclusions with those of steel in which they are included. To fully justify the need for experimental research, it should be mentioned that steel is currently one of the most used alloys in modern society [ 1 , 12 , 13 , 14 ].…”