Study Of High Performance Auto-steel Stamping Parts Based On Lightweight Assessment

It is necessary to carry out study of lightweight assessment method and model for the acquisition of cost-performance design-material-manufacturing solutions.First design criterion for lightweight high strength auto-steel sheets and stamping parts is choosing high specific strength steel sheets.The index function of r=r0+Ae-kR is obtained by nonlinear fitting,which is the variable of yield strength and tensile strength respectively of high strength auto steel sheets.The larger the weight reduction coefficient,the better the light weight effect.The proposed performance weight method can be quantified for performance evaluation.By introducing performance weighting factors,some qualitative performance evaluation indexes are converted into quantitative comparison values.Establish a lightweight assessment model for weight reduction,cost and environmental impact indicators due to increased strength.Based on the lightweight assessment and stress analysis of yield strength,the lightweight approach of 380L steel cross beam was substitued by the TG750 third generation auto-steel.The shape of the cross beam after light weighting is unchanged,the thickness is reduced by 1mm,and the weight reduction is about 16.7%.A TG750 hot rolled steel sheet is successfully developed up to 29.5GPa%.With the high strength and high plasticity of TG750 steel,improves the forming properties of steel sheets,and effectively prevents the forming edges from cracking.With the increase of strength,the delay fracture and fatigue performance of TG750 steel should be taken seriously.After the bench test,the cross beams and the joints are in good condition.Results of the lightweight solution are proved to be good.The weight reduction coefficient of hot forming side door beam with tensile strength is increased.The weight reduction coefficients of the four intensities of the 1500,1700,2000 and 2200MPa are 037?0.73.Study the key hot forming process and carry out die optimization design.Performance evaluation of hot forming parts:as the tensile strength increases,the resistance to the beam static pressure increases,the welding performance meets the requirements,delays fracture and fatigue performance are reduced.The paper analyses the steel sheet and forming process characteristics of the type 0.1C-5Mn warm forming B-pillar.Design optimization temperature forming process and die structure.Warm forming parts are trial fabricated in hot forming line.The production cost of hot forming and warm forming B-pillar is slightly higher than that of cold stamping B-pillar,but it is very effective in improving performance,reducing weight and carbon emissions.With the same weight reduction,manufacture cost,energy consumption and performance of warm forming parts are better than that of hot forming parts.According to the performance weighting method,the factors such as invasion distance,absorbing energy,contact reaction force and safety are considered.To achieve the high performance cost effective hot forming parts,the lightweight design and manufacturing solution for the tailored hot forming A1700 side door beam is confirmed.Microstructure and performance of tailored hot forming parts are comparable to that of design values by successfully trial production.