Research on the Effect of Banded Structure on the Micro-structure and Mechanical Properties of 42CrMoA in the Tempering State
To study the influence of banded structure on the micro-structure and mechanical properties of 42CrMoA after quenching and tempering,this article selects two hot-rolled bars with different banded structure grades,treats them with the same quenching and tempering process.Samples were prepared before and after treatment according to the requirements of the national standard,and the micro-structures and mechanical properties were tested and analyzed.The results indicate that:(1)the micro-structure after quenching and tempering is tempered sorbite,but there is still segregation;(2)the mechanical properties and hardness are improved after quenching and tempering,but the parts with severe banded structure show instability in strength,toughness,and hardness,especially affecting the impact resistance,which is not conducive to the control of product quality stability;(3)routine inspections such as composition analysis,hardness,tensile test,and impact test cannot accurately determine the banded structure grade.It is recommended to add metallographic structure inspection after the raw materials enter the factory;(4)the banded structure grade of raw materials should be strictly controlled.It is recommended to control the banded structure below grade 2 for parts with higher comprehensive performance requirements.
42CrMoAbanded structurequenching and tempering treatmentmicro-structuremechanical properties
NETL
NSTL
万方数据
