Study on dislocation density during the cold roll-beating of 40Cr steel

摘要

In order to improve the quality of 40Cr steel formed by cold roll-beating, the relationship between the cold roll-beating flow stress and the dislocation density of 40Cr was established. Curves of changes in 40Cr dislocation density at different strain rates were obtained from the stress-strain curve of cold roll-beaten 40Cr material; the model of changes in microscopic dislocation density was established based on the flow model of macrostress. The curves of changes in dislocation density at different strain rates were obtained from calculations, and the experimental and calculated values of the dislocation density were compared and analyzed while the accuracy of the model was verified. XRD spectra of 40Cr formed with different cold roll-beating parameters were combined with the Dunn-Koch formula to obtain the dislocation density of various crystal faces and the crystal surface as a whole. Results of the analyses are used to explain the plastic flow mechanism in cold roll-beating of 40Cr from a microscopic point of view.