Effect of Austenitization Temperature on Hot Ductility of C-Mn-Al HSLA Steel

The article aims to investigate the effect of different austenitization temperatures on the hot ductility of C-Mn-Al High-Strength Low-Alloy (HSLA) steel. The thermo-mechanical simulator of physical processes Gleeble 1500D was used for steel hot ductility study. Hot ductility was estimated by measuring the reduction of area after static tensile testing carried out at temperatures in the range 600 degrees C to 1200 degrees C with the step of 50 degrees C. Evaluation of fracture surfaces after austenitization at 1250 degrees C and 1350 degrees C with a holding time of the 30 s showed significant differences in the character of the fracture as well as in the ductility. The fracture surfaces and the microstructure near the fracture surfaces of samples at a test temperature of 1000 degrees C for both austenitization temperatures were analyzed by Scanning Electron Microscopy (SEM), Light Optical Microscopy (LOM), and AZtec Feature analysis (particle analysis of SEM). AlN and AlN-MnS precipitates at grain boundaries detected by the detailed metallographic analysis were identified as the main causes of plasticity trough in the evaluated steel. Moreover, using Thermo-Calc software, it was found that AlN particles precipitate from solid solution below the temperature of 1425 degrees C.

Automated summary

This study investigates the effect of different austenitization temperatures on the hot ductility of C-Mn-Al High-Strength Low-Alloy (HSLA) steel, with a focus on the importance of details in ductility, fracture surface characteristics, and microstructure of the steel. Metallographic analysis revealed that AlN and AlN-MnS precipitates at grain boundaries are the main causes of plasticity trough in the evaluated steel.