Recrystallization of AISI 304 Stainless Steel in the Steckel Mill Rolling Process
Supervised by A/Prof R Knutsen and funded by Columbus Steel, Sa-Aadat's work explores the relationship between recrystallisation and hot rolling of 304 steel.The steckel mill is a hot rolling mill that reduces metal plate thickness. Columbus Stainless possesses such a mill to reduce its stainless steel plates. The designation of the steel is AISI 304 and this indicates the composition of the steel. The properties and structure of the stainless steel change in this reduction operation. Recrystallization is a softening process that happens at high temperatures and is affected by the process variables, such as temperature, strain, time and strain rate. By understanding the process variables effect on recrystallization, the properties of the metal can be predicted. Various methods experimental were used to determine the extent and type of recrystallization. These include microhardness testing, light microscopy and a special technique on the Scanning Electron Microscope, called Electron Backscatter Detection (EBSD). Data, in terms of temperature and loads from the steckel mill was also used to calculate the Mean Flow Stress (MFS). The MFS is good indicator of whether microstructural events like recrystallization are occurring.