During the cold-drawing process, metallic materials are subjected to various changes in their mechanical properties due to the accumulation of residual strains. Some considera ions on the cause of such changes were made in the present report by means of the X-ray analysis, which was performed by the back-reflection-focussing method concerning various kinds of cold-drawn carbon steel bars. Results of the experiment were as follows:
1) Residual strains of the first kind, having the small gradient of strain distribution, increase very rapidly in the specimen subjected to the reduction between 0 and 15%, then slowly and finally reach the saturated state when the reduction rate exceeds 20%.
2) The saturated residual strains show the higher value as the carbon, content of the cold-drawn bar increases.
3) Residual strains of the second kind, having the large gradient of strain distribution, increase rapidly in the specimens subjected to the reduction between 0 and 15%, and then slowly up to the maximum reduction of 30%.
4) Residual strains of the second kind in some specimens with a certain reduction rate always show the higher value as the carbon content of cold-drawn bar increases.
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