Effect of Carbide Precipitation on “Precipitation Plasticity” and Residual Stress during Tempering

Abstract

Tempering is an important method for controlling the residual stress of metallic materials. Experience has indicated that increasing the tempering temperature and extending the tempering time reduces the residual stress. However, the micromechanism of residual stress evolution during tempering is not well understood.Ritter et al. [1] believed that the changes in the mechanical behavior of a material during tempering are the main reason for the relaxation of residual stress and attempted to reveal the internal mechanism of the residual stress evolution by studying the changes in the elastic modulus, yield strength, and creep behavior of the material during the tempering process. This study also provides a theoretical basis for reducing the residual stress distribution by increasing the tempering temperature and extending the tempering time. In 2009, Morra et al. [2] studied the tempering of Society of Automotive Engineers 52 100 and found that irreversible plastic deformation similar to phase transformation plasticity occurred as the nanoscale carbides in the material coarsened. This study introduced a new perspective for the research on tempering residual stress. However, since carbide coarsening inevitably leads to worse mechanical properties in materials, the work of Morra et al. has not attracted widespread attention.In 2015, Yamazaki et al. [3][4][5] of the Nippon Steel Corporation and Osaka University performed tempering experiment using materials with a carbon content of 0.32-0.8 wt%. It was found that when the applied load was lower than the yield strength of the material, irreversible plasticity could be produced in the direction of the load. This plasticity was named "tempering plasticity", and it was used as a main influencing factor for the prediction of the residual stress during tempering. Subsequently, Kaiser et al. [6] of the Karlsruhe Institute in Germany considered the crystal parameters in studying the tempering of martensitic American Iron and Steel Institue 4140 steel (with a carbon (C) content of 0.453 wt%). It was confirmed that plastic behavior similar to phase transformation plasticity occurred during the cementite precipitation stage in the tempering process. Based on this study, Kaiser et al. [7,8] employed the Greenwood-Johnson model to predict the evolution of residual stress during tempering.In the tempering process, transition carbides, cementite, alloy carbides, and other carbides precipitate as the tempering temperature increases. [9][10][11] The precipitation and evolution of carbides in the previous stage directly affect the growth of carbides in the subsequent stage. Moreover, the plastic behaviors caused by the precipitation, coarsening, and dissolution of carbides are different. To reduce the influence of complex structural transformation on plastic behavior, Ding et al. [12][13][14] investigated low-carbon steel with a carbon content of only 0.07 wt%. The irreversible plastic behavior during the precipitation of carbides was confirmed by tempering dilatation tests, microstruc...

Multiscale simulation and experimental measurements of the elastic response for constructional steel

“…) Simultaneous Equation. ( 6), the strain disturbance can be obtained from 𝜺 𝑖𝑗 ′ = 𝑻 𝑖𝑗𝑘𝑙 : 𝝈 ̅ 𝑘𝑙 (13) where…”

Intervention mechanism of carbide precipitation during tempering and its impact on residual stress and mechanical properties of wear-resistant steels

“…Subsequently, Kaiser et al [9][10][11] found that plastic behaviour similar to phase transformation plasticity occurs in cementite precipitation stage during the tempering process and predicted the evolution of residual stress during tempering by the Greenwood-Johnson model. Ding et al 12,13 confirmed the existence of irreversible plastic behaviour during carbide precipitation. They further pointed out that this plastic behaviour caused by carbide precipitation is the main reason for the relaxation of residual stress during tempering.…”