Ductile fracture mechanism for dual phase steel with high strength second phase

被引：0
作者：
Shoji, Hiroto [1 ]
Hino, Keiichi [1 ]
Ohata, Mitsuru [1 ]
Shinohara, Yasuhiro [2 ]
Minami, Fumiyoshi [3 ]
机构：
[1] Graduate School of Engineering, Osaka University
[2] Joining and Welding Research Institute, Osaka University
来源：
Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society | 2015年 / 33卷 / 04期
关键词：
Dual phase steel; Ductile fracture; Micro-structural heterogeneity; Plastic strain; Stress triaxiality;
D O I：
10.2207/qjjws.33.341
中图分类号：
TG113 [金相学（金属的组织与性能）];
学科分类号：
摘要：
The purpose of this study is to discuss the effect of high strength second phase in Ferrite-Martensite dual-phase steel on ductile fracture mechanism. Ferrite and Martensite single-phase steels with the same properties as Ferrite and Martensite phases in the dual-phase steel were made. The smooth and circumferentially notched round-bar tensile tests for the steels were conducted. The Martensite single-phase steel has low ductility and toughness. However, no cleavage surface was observed in the fracture surface of round-bar tensile specimen of the dual-phase steel. The micro-voids were nucleated mainly in the Ferrite phase near Ferrite/Martensite boundary. The strain of Martensite phase in dualphase steel below fracture surface was greater than critical strain obtained by round-bar tensile test for Martensite single-phase steel. Elasticplastic analysis using 3D micro-structural model was conducted to obtain localization of stress/strain due to micro-structural heterogeneity. The plastic strain and the stress triaxiality in the Ferrite phase near Ferrite/Martensite boundary where micro-voids were nucleated in the experiments were higher than those in the other region. The Martensite phase was compressed in the perpendicular direction to loading direction due to deformation of Ferrite phase. Therefore, stress triaxiality in the Martensite phase was lower than that in the Ferrite phase.
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页码：341 / 348
页数：7
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  • [1] Shikanai N., Kagawa H., Kurihara M., Tagawa H., Influence of microstructure on yielding behavior of heavy gauge high strength steel plates, Tetsu-to-Hagane, 76, pp. 89-96, (1990)
  • [2] Inoue T., Kinoshita S., Strain partitioning and void formation in ferrite-pearlite steels deformed in tension, Tetsu-to-Hagane, 62, pp. 90-99, (1976)
  • [3] Inoue T., Kinoshita S., Observations of ductile fracture process and criteria of void initiation in spheroidized and ferrite/pearlite steels, Tetsu-to-Hagane, 62, pp. 875-884, (1976)
  • [4] Ohji K., Ogura K., Ohmori K., Nomizu T., Observations of microvoid and critical condition for its initiation in ductile fracture of high strength materials, Journal of the Society of Materials Science, 41, pp. 1094-1101, (1977)
  • [5] Tomota Y., Kawamura Y., Kuroki K., On ductile fracture of steels containing a coarse second phase, Transactions of the Japan Society of Mechanical Engineers A, 46, pp. 598-604, (1980)
  • [6] Qiu H., Mori H., Enoki M., Kishi T., Evaluation of ductile fracture of structural steels by microvoid model, ISIJ International, 39, pp. 358-364, (1999)
  • [7] Erdogan M., The effect of new ferrite content on the tensile fracture behaviour of dual phase steels, Journal of Materials Science, 37, pp. 3623-3630, (2002)
  • [8] Ohata M., Yokota M., Hirono M., Yasuda O., Toyoda M., Criterion for ductile cracking of structural steel under cyclic loading - Evaluation of ductile crack initiation for welded structures subjected to large scale cyclic loading (report 1), Quarterly Journal of the Japan Welding Society, 21, pp. 592-602, (2003)
  • [9] Ohata M., Toyoda M., Damage mechanism for controlling ductile cracking of structural steel with heterogeneous microstructure, Materials Science Forum, 512, pp. 31-36, (2006)
  • [10] Avramovic-Cingara G., Saleh C.A.R., Jain M.K., Wilkinson D.S., Void nucleation and growth in dual-phase steel 600 during uniaxial tensile testing, Metallurgical and Materials Transactions A, 40, pp. 3117-3127, (2009)
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