Graphical method based on modified maximum force criterion to indicate forming limit curves of 22MnB5 boron steel sheets at elevated temperatures
| Autor: | Duc-Toan Nguyen, Quoc Tuan Pham, Thi-Bich Mac, Tien-Long Banh, The-Thanh Luyen |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Materials science 0211 other engineering and technologies Metals and Alloys chemistry.chemical_element 02 engineering and technology 01 natural sciences Finite element simulation Stress (mechanics) chemistry Mechanics of Materials 0103 physical sciences Metallic materials Ultimate tensile strength Materials Chemistry Fracture (geology) Hardening (metallurgy) Limit (mathematics) Composite material Boron 021102 mining & metallurgy |
| Zdroj: | Journal of Iron and Steel Research International. 28:1009-1018 |
| ISSN: | 2210-3988 1006-706X |
| Popis: | A new approach for predicting forming limit curves (FLCs) at elevated temperatures was proposed herein. FLCs are often used to predict failure and determine the optimal forming parameters of automotive parts. First, a graphical method based on a modified maximum force criterion was applied to estimate the FLCs of 22MnB5 boron steel sheets at room temperature using various hardening laws. Subsequently, the predicted FLC data at room temperature were compared with corresponding data obtained from Nakazima’s tests to obtain the best prediction. To estimate the FLC at elevated temperatures, tensile tests were conducted at various temperatures to determine the ratios of equivalent fracture strains between the corresponding elevated temperatures and room temperature. FLCs at elevated temperatures could be established based on obtained ratios. However, the predicted FLCs at elevated temperatures did not agree well with the corresponding FLC experimental data of Zhou et al. A new method was proposed herein to improve the prediction of FLCs at elevated temperatures. An FLC calculated at room temperature was utilized to predict the failure of Nakazima’s samples via finite element simulation. Based on the simulation results at room temperature, the mathematical relationships between the equivalent ductile fracture strain versus stress triaxiality and strain ratio were established and then combined with ratios between elevated and room temperatures to calculate the FLCs at different temperatures. The predicted FLCs at elevated temperatures agree well with the corresponding experimental FLC data. |
| Databáze: | OpenAIRE |
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