Research On Controlling Organization Uniformity Of Axial Forgings In The Process Of Stretching

It is an important factor that forging comprehensive mechanical properties decided to its internal microstructure uniformity.The production process of large forgings includes forging,heat treatment,and other important link.And the free forging process is normally used to the forging forming.The characteristics of free forging are forging process long,local deformation,discontinuous deformation and the likes which caused that forging deformation and temperature is not uniform,leaded forging internal microstructure inhomogeneously,increased the difficulty of the subsequent heat treatment.Therefore,it is of grand significance in preparation for the heat treatment after forging that devotes continuously to research on the heavy forgings in the course of wrought deformation uniformity and microstructure evolution rules,to improve the uniformity of the forgings organization.It took forging 30Cr2Ni4 MoV steel as the research object,using Gleeble-1500 D thermal/mechanical simulation machine to do the double passes hot compression experiment which conditions of the deformation temperature of 900 ~ 1000?,strain rate of 0.01 ~ 1 s-1,and intervals of 5~60s have been obtained,to study the static recrystallization behaviors of high temperature deformation and draw out the stress-strain curve.Besides,the 2% offset method is adopted to define the static recrystallization volume fraction.Furthermore,the infection of different deformation parameters on its static recrystallization was discussed.According to the experimental results,the model of static recrystallization kinetics and recrystallization grain size of forging 30Cr2Ni4 MoV steel was established.It was used DEFORM-3D software to analyze the distribution of deformation,strain,temperature,static recrystallization volume fraction,dynamic recrystallization volume fraction and grain size at the stretching deformation process of upper flat anvil and under V-shaped anvil.Combined shrinkage ratio test to compare and analysis the emulation results and experiment results.It is resulted that with the increase of forging ratio and forging temperature,deformation and the grain size of the inhomogeneous degree increased under the forging ratio within the range of 1.1 ~ 1.3 and forging temperature within the range of 1050 ~ 1250 ?.