Study On Hot Bending Forming Mechanism Of Weathering Steel

Based on the research on the mechanical properties and physical constitutive relation of Q460 high strength weathering steel,this paper explores the influence law and physical mechanism of temperature and strain rate on the rheological properties and mechanical properties of steel metal.On this basis,the offset model of neutral layer in roll bending process of large-sized thick-walled steel plate is studied,and the application research on the problems occurred in hot bending process of large-sized thick-walled weathering steel is carried out.Through the hot compression test of Q460 steel in the temperature range of 650 ? ? 900 ?,the constitutive relation of metal rheology is established.Through the modification of the constitutive equation initially established,the high temperature constitutive equation of q460 nh which has certain reference value for high temperature deformation is obtained.Based on the deformation characteristics of medium and heavy plate,such as the total volume remains unchanged and the tangential strain increment at the stress neutral layer is zero,the concept of the strain increment neutral layer is proposed,the position of the strain increment neutral layer and the calculation formula of the radius of the strain increment neutral layer are analyzed,and the concept and the calculat ion formula of the radius of the strain increment neutral layer and the stress neutral layer are discussed.Representative test data were obtained through hot three-point bending experiments of Q460 plates with specifications of 250mm*80mm*16mm,250mm*80mm*20mm,250mm*80mm*25mm at 900?,800?,700?.Finally,with the help of abaqus finite element software,the finite element simulation of Q460 steel plate with 250mm*80mm specifications under different thicknesses and temperatures is carried out.Based on the material parameters at different temperatures obtained from experiments,the material model is constructed,and the simulation is introduced to realize the simulation of different temperature conditions.The established formula for calculating the offset of neutral layer is verified by numerical simulation analys is.The results can provide theoretical basis for the study of plastic bending deformation and thickness thinning law of plate.