Hot Deformation Behavior of Non-Alloyed Carbon Steels

Materials

Michal Sauer¹  Petr Kawulok¹  Stanislav Rusz¹  Kateřina Konečná¹  Petr Opěla¹  Rostislav Kawulok¹  Ivo Schindler¹ 

[1] Faculty of Materials Science and Technology, VŠB–Technical University of Ostrava, 17. Listopadu 2172/15, 70800 Ostrava, Czech Republic;

关键词: carbon steels;    hot flow stress curves;    dynamic recrystallization;    peak flow stress;    peak strain;    critical strain for induce of dynamic recrystallization;   

DOI  :  10.3390/ma15020595

来源: DOAJ

【 摘 要 】

The hot deformation behavior of selected non-alloyed carbon steels was investigated by isothermal continuous uniaxial compression tests. Based on the analysis of experimentally determined flow stress curves, material constants suitable for predicting peak flow stress σ_p, peak strain ε_p and critical strain ε_crDRX necessary to induce dynamic recrystallization and the corresponding critical flow stresses σ_crDRX were determined. The validity of the predicted critical strains ε_crDRX was then experimentally verified. Fine dynamically recrystallized grains, which formed at the boundaries of the original austenitic grains, were detected in the microstructure of additionally deformed specimens from low-carbon investigated steels. Furthermore, equations describing with perfect accuracy a simple linear dependence of the critical strain ε_crDRX on peak strain ε_p were derived for all investigated steels. The determined hot deformation activation energy Q decreased with increasing carbon content (also with increasing carbon equivalent value) in all investigated steels. A logarithmic equation described this dependency with reasonable accuracy. Individual flow stress curves of the investigated steels were mathematically described using the Cingara and McQueen model, while the predicted flow stresses showed excellent accuracy, especially in the strains ranging from 0 to ε_p.

【 授权许可】

Unknown