A simulation-based analysis of internal material loads and material modifications in multi-step deep rolling

摘要

The concept of Process Signatures states that material modifications are solely dependent on the acting internal loads during processing,irrespective of the specific process chosen.Knowledge of these correlations would allow the prediction of the resulting surface integrity of a process and consequently facilitate the process design.The validity of the concept was already shown for single-step processes in the past.However,more relevant to industrial praxis are multi-step processes with recurring loadings of the workpiece material under varying conditions.In those,the internal loads during a specific step interact with previously generated modifications.This has to be taken into account in the formulation of industrially relevant Process Signatures.In the present paper,3D finite element simulations are utilized to examine the influence of recurring loadings for deep rolling.Prismatic workpieces made of 42CrMo4(AISI4140)are deep rolled along consecutive tracks with different overlaps of the paths.The development of the internal material loads and the residual stresses of consecutively deep rolled tracks is determined and qualitatively compared with experimental results.The observations help to better understand the material behavior during multi-step deep rolling and are the starting point for further analyses to derive Process Signatures that incorporate the influence of recurring loads.