Study On Two-roller Straightening Process For Bar

With the rapid development of national economy, the demand of high quality bars at home and abroad is also increasing year by year. Bar in the process of rolling, heat treatment and transportation tends to produce all-round bending defects, which needs to be straightened. Two-roll straightener has the advantage of the high precision and good quality, so it always has an irreplaceable position in the field of straightening.Referring to actual production, using ABAQUS finite element software as a platform, the dynamic simulation of the two-roll bar straightened process with the curved bar model is built. The straightening stress and strain, straightening force during the process, as well as the straightening effect on residual stress and straightness were all analyzed deeply in this paper.On the basis of the finite element model, by changing the distance between the guides, roll gap, straightening speed and friction codfficient in the straightening process, variations of straightening force, degree of plastic deformation, residual stress and the maximum deflection of bar after straightening are analyzed in different process parameters. Through comprehensive analysis of the above results, it obtained reasonable method of taking value of each factor to provide guidance for the practical production.In theory, the analytic method breaks through the traditional straightening theory, The springback theory of small curvature plane bending is used in the analysis of the two-roller straightening process for bars. Combined with the classical straightening theory and proposed the calculation method of straightening force. Use the MATLAB software platform to simplify the calculation procedure and give the parsing processes of the two-roll straightening. In addition, based on the above theory, analysis the variation of plastic region ratio and the curvature of bars, the principle of the two-roll straightening process is clearly revealed by quantitative analysis. This paper provides a reliable theoretical guidance for the optimal design of roll contour and straightener.