Numerical analysis of Johnson-Cook damage model parameters effects on the cutting simulation of AISI 1045

Background: Failure model is the important basis for the research of material failure and fracture, and plays an important role in the finite element simulation of metal cutting. Johnson-Cook damage model is widely used to predict the failure of many materials. Its damage evolution is controlled by five parameters Objective: In order to decrease the cost of damage parameters identification and find out the damage parameters which have great influence on the simulation results. This work can provide an assistance in the optimization and selection of constitutive model parameters. Methods: Suitable Johnson-Cook damage model parameters, which can be used in the metal cutting simulation of AISI 1045 steel, are selected by comparing the simulation results and the experiments results. The cutting process of AISI 1045 steel is simulated by changing the Johnson-Cook damage parameters in the ABAQUS/Explicit. Results: The relevance of cutting force, feed force, cutting temperature, and deformation coefficient with five Johnson-Cook damage parameters are determined. Conclusion: The finite element simulation results show that the Johnson-Cook damage model parameters D2 and D3 have the biggest impact on the cutting simulation of AISI 1045 steel. Meanwhile, different Johnson-Cook damage parameters would take different changes to the simulation results

Kinetics of the formation of a diffusion layer on AISI 1045 steel with simultaneous saturation with boron, chromium and titanium

Research has been carried out to determine the kinetics of coating formation on AISI 1045 steel with diffusion saturation with boron, chromium and titanium simultaneously. It was found that the experimental parameters of the thickness of the diffusion layer of borides over time outstrip the calculated values. The diffusion layer has a thickness of 120 μm with a saturation duration of 2.5 h, 155 μm with a saturation duration of 5 h, and 180 μm with a saturation duration of 7.5 h. In addition to studying the kinetics of the formation of a diffusion coating, also studied the distribution of microhardness over the cross section of the diffusion coating. The maximum microhardness of the diffusion coating is observed not on the surface, but at some distance from it. On average, at a depth of 45–60 µm from the surface. In this case, the microhardness on the surface of the diffusion coating, on the contrary, tends to take on a minimum value of about 1800 HV0.1. Such a distribution of microhardness it gives the parts the possibility of minor surface wear.

A modified Zerilli–Armstrong constitutive model for simulating severe plastic deformation of a steel alloy

A modified Zerilli–Armstrong model has been proposed and validated in previous works for simulating distinct deformation mechanisms of continuous-shear and shear-localization during severe plastic deformation of a face centered cubic alloy. In this paper, the validity of the modified Zerilli–Armstrong model has been further tested by using it for modeling the severe plastic deformation of another face centered cubic material, a steel alloy. In particular, the modified Zerilli–Armstrong model is used as a constitutive relation for simulating behavior of AISI 1045 steel alloy while undergoing severe plastic deformation through orthogonal and plane-strain machining. Accordingly, the performance of the constitutive relation in predicting flow stress distribution along the primary shear zone is validated by comparing with forecasts made using the distributed primary zone deformation, the original Zerilli-Armstrong and Johnson-Cook models. Furthermore, finite element simulations of orthogonal cutting of this steel alloy were carried out, and good agreement was observed between the predicted chip morphology and attendant cutting forces with experimental values reported in literature for a range of cutting conditions. The force predictions also fared better compared to those predicted by using the Zerilli-Armstrong and Johnson-Cook models. These validations provide further corroboration of using the modified Zerilli–Armstrong model as a constitutive relation for simulating the behavior of face-centered cubic materials under conditions of high plastic strains and also high strain-rates.