FENG Pei-Hsien National Cheng Kung University

Spoluautoři ZHANG Jian, HWANG Weng-Sing, PAN Yan-Chi

Acicular ferrite is well-known to be a microstructure to increase toughness and strength for low-carbon alloy steel weld metals. Finely dispersed nonmetallic inclusions could be the nucleation sites for acicular ferrite, result in reduced grain size and consequently improve the mechanical properties of steel. In this study, 7ppm of magnesium was added into Al-killed low-carbon steel (SS400) during secondary steelmaking in order to fine-tune the composition of the steel and obtain fine particles. Hot rolling process of the steel was simulated by Gleeble 1500 Thermal-mechanical Simulator to investigate the relationship between heat treatment and formation of acicular ferrite. Furthermore, the phase constitution and microstructure of SS400 was analyzed by Scanning Electrical Microscope (SEM) and Electron Backscatter Diffraction (EBSD). Finally, the best heat treatment of SS400 steel for forming acicular ferrite has been established.