| Title |
Development of On - line Structure / Preoperty Prediction System for Hot Rolled - C - Mn Steels |
| Authors |
권오준(O . Kwon); 이경종(K . J . Lee); 강기봉(K . B . Kang); 이재곤(J . K . Lee); 이필종(P . J . Lee); 박윤순(Y . S . Park); 노근기(E . K . Ro); 민경준(K . J . Min); 이주동(J . D . Lee); 유규천(K . C . Yoo) |
| Abstract |
An on-line computer system was developed for prediction of tensile properties of C-Mn steels manufactured in the hot strip mill. To predict the final microstructure and properties in plain carbon steel hot coils, a mathematical model based on physical metallurgy was developed. Computer modelling was carried out to describe the microstrucal evolution during hot rolling and cooling and the interrelationships existing between microstructure and mechanical properties. The mathematical model consists of three sub-models : austenite conditioning model, transformation model and mechanical property model. The austenite conditioning model deals with recovery, recrystallization and grain growth which occur during hot rolling. The allotropic phase transformtaiton from austenite to ferrite, pearilte and bainite are described by the transformation model. The final mechanical properties are determined from the structure-property relationships established in the mechanical property model. An Avrami-type kinetic equation was used for mathematical representation of recrystallization and austenite/ferrite transformation. The structure-property relationship was formulated by combining the Hall-Petch equation with the mixture rule. In order to apply the model to the practical hot rolling process, an on-line computer system was installed at a hot strip mill. The on-line system consists of a high speed process computer and software packages. The predicted values of tensile strength from the system were in reasonable agreement with the measured ones when hot strips were processed under various rolling conditions. |