Dynamic Mechanical Response of CL65 Wheel Steel under Dynamic Impact

The mechanical behaviors of CL65 wheel rim material from tread to depth under different temperatures (25-600 & DEG;C) and strain rates (0.001-7000 s-1) were investigated by utilizing quasi-static tensile and split Hopkinson pressure bar tests. The Johnson-Cook model of CL65 wheel steel was fitted, and the corresponding dynamic mechanics of wheel steel was discussed. The results show that the stress-strain curves of CL65 wheel rim steel were strain rate dependent and temperature dependent that the stress increased with the increase in strain rate and decreased with the rise of test temperature. With the elevated distance from the tread, the pearlite grain size, interlamellar spacing, and volume fraction of pre-eutectoid ferrite increased, resulting in an increase in ductility of quasi-static tensile and a decrease in the strength of the materials. In addition, the thin cementite layers showed more substantial toughness than the thick cementite layers. During the plastic deformation, high temperature promoted the fragmentation and dissolution of cementite lamellae, significantly impacting the thin cementite layer more than the thick cementite, which reduced the hindrance of dislocation movement during the plastic deformation, leading to weaker strain rate sensitivity and stronger temperature sensitivity in the material near the wheel tread (Zone 1) than in the deep material (Zone 2 and Zone 3).

Automated summary

The mechanical behaviors of CL65 wheel rim material were studied under different temperatures and strain rates. The stress-strain curves were found to be dependent on strain rate and temperature. The ductility of the material increased with the distance from the tread, while the strength decreased. High temperature promoted the fragmentation and dissolution of cementite layers, leading to weaker strain rate sensitivity and stronger temperature sensitivity.