Plastic Instability in Medium-Carbon Tempered Martensite Steel

Materials

Hai Qiu¹  Yuuji Kimura¹  Tadanobu Inoue¹  Rintaro Ueji¹ 

[1] Research Center for Structural Materials, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047, Ibaraki, Japan;

关键词: Lüders deformation;    heterogeneous plastic deformation;    medium-carbon steel;    plastic instability;    digital image correlation;   

DOI  :  10.3390/ma14164609

来源: DOAJ

【 摘 要 】

Inhomogeneous plastic deformation damages the surface quality of a product in the metal forming process. Therefore, it is necessary to investigate the plastic instability of a metal. Tempered martensite is a common microstructure of medium-carbon steel. Plastic instability (Lüders phenomenon, Portevin-Le Châtelier phenomenon) in this phase was investigated by a uniaxial tension test performed at room temperature. The formation and propagation of a plastic band were analyzed via two-dimensional digital image correlation, and the strain and strain-rate fields were experimentally evaluated. The results obtained are as follows: (1) there was no clear yield plateau on the stress–strain curve; (2) Lüders phenomenon was present, but the Portevin-Le Châtelier phenomenon was not found; (3) in the Lüders deformation process, local strain distribution in tempered martensite is more complicated than that in ferrite.

【 授权许可】

Unknown