终轧及卷取温度对610MPa级汽车大梁钢组织性能的影响OA

To investigate the regulation rules of rolling process parameters on the microstruc-ture and properties of 610 MPa grade Nb-Ti strengthened automotive frame steel,finishing rolling and coiling temperature tests were carried out on this material.The effects of different finishing roll-ing temperatures and coiling temperatures on the mechanical properties,ferrite grain size,and mi-crostructure of the tested steel were systematically analyzed using metallographic microscopy,scan-ning electron microscopy,and electronic tensile testing machines.The results show that the micro-structure of the tested steel consists of ferrite and pearlite.With the increase of coiling temperature,the ferrite grains grow and the morphology gradually changes from elongated to nearly polygonal,while the yield strength and tensile strength generally show an upward trend.Lowering the finishing rolling temperature is beneficial to the refinement of ferrite grains.Considering the matching of strength and plasticity,control of banded structure,hot-rolled strip shape,and industrial produc-tion stability,a finishing rolling temperature of 880℃and a coiling temperature of 560℃were de-termined as the optimal hot rolling process for this steel grade.This study can provide a theoretical basis and practical reference for the optimization of industrial production processes for 610 MPa grade series automotive frame steels.