.42 Of Crmo Ring Solidification Process Of Numerical Simulation And Experimental Study

Ring rolling directly by means of annular castingblank is an efficient,material-efficieny,energy-efficieny production technology of rings. The casting process has high requirements for the annular castingblank.Its performance has a direct relationship to the quality of subsequent rolling forming.In this paper,two sand casting processes and one centrifugal casting process were designed according to the requirement of 42CrMo bearing rings.At last,the bottom gating system and annluar iron were proved to be the most reasonable process.The main research contents and results are as follows:The melting process of 42CrMo was analyzed and the proportion of alloying elements were identified: Mo:5kg/T, Cr:5kg/T, Si:5 kg/T, Mn: 5kg/T, Al:1.2~1.5 kg/T.At the same time,the coating are decided to be alcohol sodium silicate sand. The bottom gating system with anular irons and top gating system were analyzed in theory.The size of risers, position of anular and the size of runner were designed.The rotation speed and filling time of vertical centrifugal casting were also determined.The results of numerical simulation showed that shrinkage and other defects would remain in the casting when top gating system was used.The quality of casting was be also impacted. When bottom gating system,appropriate riser and cold iorns were used together, the cooling rate of casting will be accelerated and the bottom-up order of solidification will be also achieved.Metallographic observation and mechaincal properties showed that microstruture of 42CrMo were good. The main properties are as follows: ReH=61 MPa,σ_b=782 MPa,δ=6.33%,φ=18%,HB=232,these meet the expected requirements.The properties after rolling were basically same to the traditonal production process.The design was succeed.The gain of sand casing process laid a good foundation for ring rolling directly by means of annular castingblank and provided possobility for the success of the cast-forming composite techology. It has the advantage of energy-saving,low-carbon and improved the efficiency of production,which will have an obvious market competition prospect.