Microstructural evolution and formation mechanism of bimodal structure of 0.2% carbon steel subjected to the heavy-reduction controlled rolling process

作者：Park Hyung Won^*; Shimojima Kei; Sugiyama Sumio; Komine Hisanao; Yanagimoto Jun

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2015, 624: 203-212.

DOI：10.1016/j.msea.2014.11.070

• Low-carbon steel
• Bimodal structure
• Severe plastic deformation
• Controlled-rolling process
• Thermomechanical processing
• Plane-strain compression

A heavy-reduction controlled rolling process with approximately 75% thickness reduction was carried out to investigate the microstructural evolution including texture development, focusing on the formation of a bimodal structure of 0.2% carbon steel with heating temperatures of 700, 800, 900, and 1000 degrees C. Upon increasing the heating temperature from 700 to 900 degrees C, the microstructure was refined and precipitates such as Fe3C were uniformly distributed throughout the microstructure. For the microstructures control-rolled at heating temperatures of 900 and 1000 degrees C with average ferrite grain sizes of 1.34 and 1.63 mu m, respectively, a bimodal structure could be observed by scanning electron microscopy (SEM), which was very similar to the result of a plane-strain compression (PSC) test. Moreover, the 900 and 1000 degrees C-heated specimens had less well developed textures primarily consisting of {113}-{4 4 11}< 110 > and {332}< 113 > components, which usually developed by the transformation (gamma ->alpha), and the 1000 degrees C-heated specimen exhibited various textures and a low intensity of the {100}(011) component, which was generally transformed from the {100}< 001 > component of the recrystallized austenite.

• 出版日期2015-1-29