Study On The Behavior Of 51CrV4 Spring Steel Inclusions And Second Phase

With the develop of auto industry,our country in general strength,high strength spring steel production technology is mature,get a lot of innovation,and promote the industrialization,but in view of the ultra high strength,high quality grades of spring steel process technology is still not fully breakthrough,and far from industrialization level,still have a lot of basic technology,engineering technology need to research and development.In this paper,the other big 51CrV4 spring steel,special steel production technology has carried on the related research,the basis of the analysis mainly includes the typical inclusions and second phase precipitation rule and austenite dynamic recrystallization law research.The final results of this thesis research for the big 51CrV4 spring steel of high strength high quality spring flat steel production to provide technical support,in order to achieve the whole production process technology,the results show that:Microscopic inclusions mainly form,class,globose,quantity is more,according to the statistical results of microscopic inclusions,under ten microns accounted for the vast majority of microscopic class mainly part of MnS inclusions species,a small amount of Al₂O₃ inclusions,Al₂O₃-CaO-SiO₂ composite inclusion in the majority.Large inclusion content is higher,mixed types mainly include CaO classes;Al₂O₃-SiO₂-Cr₂O₃-CaS-FeS composite inclusions;?Cr,V?₂O₃-SiO₂-FeS composite inclusions;SiO₂-CaO-Cr₂O₃-Al₂O₃-MgO style composite inclusions;Al₂O₃-SiO₂-TiO composite inclusions;Al₂O₃ inclusions or Al₂O₃-CaO inclusions;Al₂O₃-SiO₂ inclusions and silicate inclusions;When calculating the temperature range of main precipitated phase are: FCC_A1,MnS,FCC_A1#2,BCC_A2,M₇C₃,DIAMOND_FCC_A4,M₂₃C₆,FCC_A1,M₃C₂.Alloy element content of Cr and V of the change of precipitation phase MnS,BCC_A2 and FCC_A1 has almost no effect,the precipitated phase of FCC_A1#2,M₇C₃ and M₃C₂ influence is bigger.The Cr content on the FCC_A1#2 precipitated phase,start leaching temperature,maximum precipitation amount and the maximum amount of precipitation temperature,with the increase of V content increases;V content on M₃C₂ and M₇C₃ precipitated phase related parameters,as the largest amount precipitation increases with increasing of the content of Cr,Cr content has a little influence on precipitation of other related parameters;When other compression deformation parameters of a certain deformation temperature at 800-950 ?,under the technological conditions of average austenitic grain diameter decreases with theincrease of deformation temperature and deformation in the 950 ? temperature get minimum grain diameter,grain size;Under 0.01-1 S-1deformation rate,with the increase of strain rate,the austenitic grain diameter decreased;When the deformation rate is higher than 1 S-1,the austenitic grain diameter increasing;When other deformation process parameters must,with the increase of strain values,grain diameter,grain size increases.