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Vol.42, No.2, 117 ~ 127, 2004
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| Title |
| Quasi-static and Dynamic Deformation Behavior of Tempered Dual Phase Steels |
| 이한상 Lee Han Sang , 황병철 Hwang Byeong Cheol , 이성학 Lee Seong Hag , 이창길 Lee Chang Gil , 김성준 Kim Seong Jun |
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| Abstract |
| Effects of martensite morphology and tempering on quasi-static and dynamic deformation behavior of dual phase steels were investigated in this study. Dynamic torsional tests were conducted on six steel specimens, which had different martensite morphology and tempering effect, using a torsional Kolsky bar, and then the test data were compared via microstructures, tensile properties, and fracture mode. In the intermediate annealed (IA) specimens, small martensites were well distributed in the ferrite matrix, but bulky martensites were mixed with ferrites in the step quenched (SQ) specimens. Under a dynamic loading condition, the fracture mode of SQ-specimens was changed from cleavage to ductile fracture as the tempering temperature increased, whereas IA-specimens had a ductile fracture mode, irrespective of tempering. These phenomena were analyzed using a rule of mixtures, phase continuity, and interfacial strength between martensite and ferrite. |
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| Key Words |
| Dual phase steel, Tempering, Dynamic deformation, Martensite, Ferrite, Step quenching, Intermediate annealing |
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