Session: 02-07-02: Advanced Material Forming: Roll Forming

Paper Number: 68789

Start Time: Thursday, 05:20 PM

68789 - Formation and Control of Defects on the Surface of Hollow Axles by Three-Roller Skew Rolling 

The main form of defects on the surface of three-roller skew rolled hollow axles is spiral marks. The spiral marks on the surface of hollow axles will reduce the mechanical properties of hollow axles, increase the machining allowance for subsequent machining, and waste materials. Severe spiral marks will cause hollow axles to be scrapped. In order to control the formation and deterioration of spiral marks, it is necessary to research on the forming mechanism of hollow axles by three-roller skew rolling. Firstly, through the kinematics analysis of the three-roller skew rolling hollow axles, the forming mechanism of the spiral marks on the surface of the hollow axles is explained. The process parameters and roller shape are the main factors for the formation of spiral marks. Secondly, through simulation, the influence of process parameters on spiral marks is analyzed. The process parameters that affect spiral marks include the rotation speed of the roller, the roller diameter, the rolled piece diameter, the feed angle and the rolled piece axial traction speed. Thirdly, by analyzing the main process parameters that affect the depth of spiral marks, the conditions for preventing spiral marks are obtained. The shape of the roller is designed from a disc to a drum, and the generatrix of the finishing section of the roller is a hyperbola. When the optimized roller is working, the finishing section of the roller fits more closely with the processed area of the rolled piece, which will improve the surface quality of the rolled piece. Finally, according to the theoretical analysis and simulation results, the optimal roller shape and process parameters that minimize the depth of the spiral mark are obtained. The research results show that the spiral pitch of the rolled piece is larger than the width of the finishing section of the roller, which is the main reason for the spiral marks on the surface of the hollow axles. The spiral pitch of the rolled piece is smaller than the width of the finishing section of the roller, which is a necessary condition to prevent the spiral marks on the surface of the hollow axles. In order to avoid the appearance of spiral marks on the surface of the hollow axles, the pitch of the rolling piece can be reduced by increasing the rotation speed of the roller. After optimizing the process parameters and roller shape, the surface quality, production efficiency and material utilization of the three-roller skew rolled hollow axles have been improved.

Presenting Author: Song Zhang Ningbo University

Authors:

Song Zhang Ningbo University
Xuedao Shu Ningbo University
Jitai Wang Ningbo University
Caoqi Ye Ningbo University