Recent research published in ‘Teshugang’, which translates to ‘Steel and Iron’, has unveiled significant advancements in the hot rolling process of low-strength interstitial-free (IF) steel, a material increasingly vital in the construction sector. Conducted by a team of experts from the State Key Laboratory of Metal Materials and Application for Marine Equipment, Anshan Iron and Steel Research Institute, and Bayuquan Iron and Steel Branch Company, this study sheds light on how the ferrite zone rolling process can enhance the mechanical properties and microstructure of IF steel.
The research focused on comparing two hot rolling processes and their effects on the metallographic microstructure, precipitation phases, and macroscopic texture of low-strength IF steel. Utilizing advanced techniques such as Optical Microscopy (OM), Transmission Electron Microscopy (TEM), and X-ray Diffraction (XRD), the team, led by Liu Gan and his colleagues, observed distinct differences in the characteristics of the steel produced under varying conditions.
“Hot-rolled IF steels in the austenitic zone exhibited equiaxed grains, while those in the ferrite zone displayed elongated and fibrous grains along the rolling direction,” Liu noted. This distinction is crucial as it influences the steel’s performance in various applications, particularly in construction, where strength and durability are paramount.
The study revealed that optimal process parameters for ferrite zone rolling include a heating temperature of 1,150 °C, a final rolling temperature of 800 °C, and a coiling temperature of 720 °C. These conditions led to a significant reduction in yield strength, with the size of precipitated phases increasing to 70-85 nm. This enhancement in microstructure is expected to improve the steel’s formability, making it particularly advantageous for deep drawing applications, a common requirement in the construction industry.
Moreover, the research found that cold-rolled annealed IF steel demonstrated a stronger γ texture, with a notable increase in the corresponding r value by 0.64 and a decrease in △r value by 0.35. Such improvements in texture and mechanical properties directly translate to better performance in construction applications, where steel components must endure significant stress and deformation.
This groundbreaking work not only provides valuable insights into the production of low-strength IF steel but also paves the way for its wider application in the construction sector. As the demand for high-performance materials continues to rise, this research offers a technical reference that could revolutionize steel production processes, ultimately leading to safer and more durable structures.
For further details about the research and its implications, you can visit the affiliations of the lead authors at State Key Laboratory of Metal Materials and Application for Marine Equipment and Bayuquan Iron and Steel Branch Company of Angang Steel Co., Ltd.. The findings underscore the potential for innovative developments in steel processing, setting the stage for future advancements in the field.
