@article{oai:yamagata.repo.nii.ac.jp:00000398, author = {武田, 武信}, issue = {2}, journal = {山形大学紀要.工学}, month = {Feb}, note = {論文(Article), Tubular specimens of prestrained mild steel are aged under stress states along the Bauschinger curve, at various temperatures below 175℃. The reversed stress imposed on the specimen durirlg aging is called here the aging stress. Reloading tests in the forward and reverse direc-tions are carried out at room temperature, and the critical aging stress at which the yield stresses in the two reloading directions become equal is determined as a function of aging temperature and prestrain. The critical aging stress normalized by the prestress decreases with increasing aging temperature and then becomes constant at aging temperatures above l00℃. The aging index, i.e., the ratio of yield sfress to prestress, rises with increasing aging temperature and approaches a saturation value at 15O℃. When the specimens are aged at 150℃, the critical aging stress normalized by the prestress remains essentially constant independent of the amount of prestrain. Although the aging index is greriter in the stress-aged steel than in the stress-relief annealed steel, the anisotropic yield surfaces of the two steels have similar forms. The results show that stress aging is an effective method for reducing the Bauschinger effect while preserving the hardening in the same direction as prestrain.  Key Words: material testing, ferrous metal (Fe-C), deformation-load property, tension test, compression test, torsion test, stress aging, Bauschinger effect, multiaxial loading test, yield criterion}, pages = {83--92}, title = {応力時効による軟鋼の強度制御}, volume = {29}, year = {2007} }