Heat Treatment of Metals ›› 2025, Vol. 50 ›› Issue (2): 268-277.DOI: 10.13251/j.issn.0254-6051.2025.02.044

• COMPUTER APPLICATION • Previous Articles     Next Articles

Prediction of critical temperature A1 and A3 of medium-Mn steel based on machine learning models

Zhang Zhiye1, Wang Yan2, Zhang Biao1, Ji Ze1, Liu Yaliang1, Zhang Minghe1, Feng Yunli1   

  1. 1. College of Metallurgy and Energy, North China University of Science and Technology, Tangshan Hebei 063210, China;
    2. Shijiazhuang Customs Technology Center Caofeidian Business Department, Tangshan Hebei 063205, China
  • Received:2024-03-15 Revised:2024-12-06 Published:2025-04-10

Abstract: In order to facilitate the design of heat treatment process of medium-Mn steel, a machine learning model for predicting the critical temperature A1 and A3 of medium-Mn steel was optimized. The critical temperature data of 496 groups of medium-Mn steels with different compositions were obtained by Thermal-Calc simulation software. Mn, Al and C compositions were taken as input characteristics, and phase transition temperatures A1 and A3 were taken as output targets. Three indexes of root mean square error (RMSE), mean absolute error (MAE) and determination coefficient (R2) were used to evaluate the prediction effect of the model. From seven machine learning models (LR, DT, SVM, GPR, Boosting, Bagging and ANN), the GPR model for predicting A1 and the GPR and ANN model for predicting A3 were screened. The results show that the GPR model for predicting A1 has sufficient accuracy, that is the optimal model for A1. The grid search method is used to adjust the hyperparameters of the preliminary model for predicting A3, and the optimal model of A3 (single-layer ANN model) is obtained. According to the chemical composition of medium-Mn steel in the applied literature, A1 and A3 are predicted by using the optimal model. The overall MAE of the predicted value and measured value of A1 and A3 is 9.95 ℃ and 13.57 ℃, respectively, and the minimum difference is 0.30 ℃ and 6.20 ℃, respectively, indicating that the model has high accuracy and can be used to predict the critical temperature of medium-Mn steel.

Key words: machine learning, medium-Mn steel, critical temperature, parameter adjustment

CLC Number: