Numerical analysis of helical rolling processes for producing steel balls

The paper discusses helical wedge rolling processes for producing balls. The design of rolls for helical wedge rolling is described. Two types of tools are distinguished: tools with conventional flanges (currently used in the industry) and tools with wedge-shaped flanges (designed at the Lublin University of Technology). The paper presents the results of experiments wherein the tools with wedge-shaped flanges were used and balls with a correct shape were produced. Two variants of rolling with the two types of tools were modelled by finite element method. Based on the results obtained (the distributions of effective strain, temperature, material failure criterion, forces and rolling moments as well as the degree of roll wear), advantages and disadvantages of the discussed rolling methods are presented.