Heat transfer coefficients of quenching oil LBA 15C and MT355 was calculated by reverse heat transfer through cooling characteristic curve.The variation of microstructure,temperature difference and deformation at different positions of 18Cr2Ni2MoVNbA steel C-type specimens during quenching with two kinds of quenching oils were calculated by finite element method,and the simulation results were verified by microstructure analysis,deformation and hardness measurement after quenching test.The results show that when using the two kinds of quenching oils,the microstructure of the carburized 18Cr2Ni2MoVNbA steel after quenching is mainly martensite,and the martensite content after quenching with quenching oil LBA 15C is slightly higher than that with quenching oil MT355,which is due to the faster cooling rate of quenching oil LBA 15C.After quenching,the notch of C-type specimens is shrinkage deformation,and the thermal stress and deformation of the specimens quenched with quenching oil LBA 15C are larger than that with quenching oil MT355.Considering the microstructure,stress and deformation,MT355 quenching oil should be selected for quenching.
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