Solutions for the Global Metals Industry

Material Properties Prediction SystemMaking High-Strength Steels at Lower CostSteel researchers are continually developing high-strength rolled steels for applications such as automobile bodies. A wayto predict the microstructure and mechanical properties of these steels would allow the production of fine grain size withhigh strength using lower grade metal. Only small quantities of additional alloying elements would be required.An integrated system combining simulation of the hot rolling process withprediction of the microstructure of the hot rolled steel has been developed byTMEIC, enabling the development of new production processes for fine grain sizesteel. The system has been proven in predicting grain size.The two steel micrographs shown here illustrate coarse grain structure (lowstrength) and fine grain structure (high strength).Course GrainStructureFine GrainStructureThe Material Properties Prediction System has Two Main PartsRolling Process Modeling SystemThis system evaluates rolling force, torque, power, etc., using equations modeling the rolling process. The calculation usesnumerical methods and is based on a specified distribution of roll forces and temperatures among the stands.Rolled Steel Microstructure Prediction SystemThis system performs metallurgical calculations taking into account the rolling and subsequent cooling processes. Theprocess phenomena include static and dynamic recrystallization, grain growth, and the austenite-ferrite transformation.Typical Prediction ResultsFinisherLaminarCoolingTemperature1050-grainCASE -B750 -grainCASE-A680880 Deformed- grainFerrite+pearlite structure720640Sub- grainsin- grain Fine ferrite+pearlite structureTimeEffect of Rolling & Cooling on Grain StructureTransition of austenitic graindiameter with deformation.Upper plot 850°, Lower 950°C.Transition of volume fractionin each structure withdeformation.Upper plot 850°, Lower 950°C.© 2011 TMEIC Corporation. All Rights Reserved.Page 15 of 40