Effect of pre-bending deformation on mechanical properties of complex phase steel CP800
Hao-fei SUN1,2, Zhi XIAO1,2,*(), Kai WEI2, Xu-jing YANG2, Jun QI3
1 State Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401122, China 2 State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China 3 Shanghai Huizhong Automobile Manufacturing Co., Ltd., Shanghai 201814, China
The pre-bending specimens were obtained by stamping with complex phase steel CP800, and the effect of pre-bending deformation on microstructure, residual stress and mechanical properties of the steel were studied by using EBSD, X-ray residual stress measurement system, tensile testing machine, DIC technique, etc. The results show that the distribution of residual stress of pre-bending specimens exhibits stress distribution of tension-compression-tension-compression, which means that the inside surface (compression layer) is tension stress and outside surface (tension layer) is compression stress. Such special distribution leads to a 16% reduction of yield stress of specimens after pre-bending. Meanwhile, due to the dislocation strengthening and hardening caused by cold deformation, the elongation of material decreases by 25% and the tensile strength increases by 24% after pre-bending. Furthermore, it is found that the inside surface produces greater plastic strain and is broken earlier than the outside surface due to the existence of tensile residual stress.
LI S C , ZHANG Y H , QI L , et al. Effect of single tensile overload on fatigue crack growth behavior in DP780 dual phase steel[J]. International Journal of Fatigue, 2018, 106, 49- 55.
doi: 10.1016/j.ijfatigue.2017.09.018
2
SHARIFIMEHR S , FATEMI A , CHA S C , et al. Fatigue behavior of AHSS lap shear and butt arc welds including the effect of periodic overloads and underloads[J]. International Journal of Fatigue, 2016, 87, 6- 14.
doi: 10.1016/j.ijfatigue.2015.12.009
3
De DIEGO-CALDERÓN I , SANTOFIMIA M J , MOLINA-ALDAREGUIA J M , et al. Deformation behavior of a high strength multiphase steel at macro- and micro-scales[J]. Materials Science and Engineering: A, 2014, 611, 201- 211.
doi: 10.1016/j.msea.2014.05.068
4
AYDIN H , ESSADIQI E , JUNG I H , et al. Development of 3rd generation AHSS with medium Mn content alloying compositions[J]. Materials Science and Engineering: A, 2013, 564, 501- 508.
doi: 10.1016/j.msea.2012.11.113
5
KARELOVA A , KREMPASZKY C , WERNER E , et al. Hole expansion of dual-phase and complex-phase AHS steels-effect of edge conditions[J]. Steel Research International, 2010, 80 (1): 71- 77.
6
ZHAO J , JIANG Z . Thermomechanical processing of advanced high strength steels[J]. Progress in Materials Science, 2018, 94, 174- 242.
LI J X , WANG W , ZHOU Y , et al. A review of research status of hydrogen embrittlement for automotive advanced high-strength steels[J]. Acta Metallurgica Sinica, 2020, 56 (4): 444- 458.
8
HELLER T , NUSS A . Effect of alloying elements on microstructure and mechanical properties of hot rolled multiphase steels[J]. Ironmaking & Steelmaking, 2005, 32 (4): 303- 308.
9
LI X , RAMAZANI A , PRAHL U , et al. Quantification of complex-phase steel microstructure by using combined EBSD and EPMA measurements[J]. Materials Characterization, 2018, 142, 179- 186.
doi: 10.1016/j.matchar.2018.05.038
10
ERICE B , ROTH C C , MOHR D . Stress-state and strain-rate dependent ductile fracture of dual and complex phase steel[J]. Mechanics of Materials, 2018, 116, 11- 32.
doi: 10.1016/j.mechmat.2017.07.020
11
SCHMITT J H , IUNG T . New developments of advanced high-strength steels for automotive applications[J]. Comptes Rendus Physique, 2018, 19 (8): 641- 656.
doi: 10.1016/j.crhy.2018.11.004
12
LAMBERS H G , RVSING C J , NIENDORF T , et al. On the low-cycle fatigue response of pre-strained austenitic Fe61Mn24Ni6.5Cr8.5 alloy showing TWIP effect[J]. International Journal of Fatigue, 2012, 40, 51- 60.
doi: 10.1016/j.ijfatigue.2012.01.002
13
ROBERTSON L T , HILDITCH T B , HODGSON P D . The effect of prestrain and bake hardening on the low-cycle fatigue properties of TRIP steel[J]. International Journal of Fatigue, 2008, 30 (4): 587- 594.
doi: 10.1016/j.ijfatigue.2007.06.002
14
SONG S W , LEE J H , LEE H J , et al. Enhancing high-cycle fatigue properties of cold-drawn Fe-Mn-C TWIP steels[J]. International Journal of Fatigue, 2016, 85, 57- 64.
doi: 10.1016/j.ijfatigue.2015.12.007
15
LY A L , FINDLEY K O . The effects of pre-straining conditions on fatigue behavior of a multiphase TRIP steel[J]. International Journal of Fatigue, 2016, 87, 225- 234.
doi: 10.1016/j.ijfatigue.2016.02.004
16
DAS B , SINGH A , PAUL S K . Low cycle fatigue performance of DP600 steel under various pre-straining paths[J]. International Journal of Fatigue, 2020, 132, 105331.
doi: 10.1016/j.ijfatigue.2019.105331
17
WANG B , ZHANG P , DUAN Q Q , et al. High-cycle fatigue properties and damage mechanisms of pre-strained Fe-30Mn-0.9C twinning-induced plasticity steel[J]. Materials Science and Engineering: A, 2017, 679, 258- 271.
doi: 10.1016/j.msea.2016.10.043
ZHANG X F , LI G A , LU Z , et al. Effect of preaged stretch after quenched on the properties and microstructure of a naturally aged Al-Li alloy[J]. Acta Metallurgica Sinica, 2016, 52 (12): 1497- 1502.
19
SUN H F , WEI K , YANG X J , et al. Effects of pre-strain and annealing on the fatigue properties of complex phase steel CP800[J]. International Journal of Fatigue, 2019, 131, 105364.
20
DAS B , SINGH A , ARORA K S , et al. Influence of pre-straining path on high cycle fatigue performance of DP 600 steel[J]. International Journal of Fatigue, 2019, 126, 369- 380.
doi: 10.1016/j.ijfatigue.2019.05.017
21
SUPPAN C , HEBESBERGER T , PICHLER A , et al. On the microstructure control of the bendability of advanced high strength steels[J]. Materials Science and Engineering: A, 2018, 735, 89- 98.
doi: 10.1016/j.msea.2018.07.080
22
HABIBNEJAD-KORAYEM M , JAIN M K , MISHRA R K . Large deformation of magnesium sheet at room temperature by preform annealing, part Ⅱ: "bending"[J]. Materials Science and Engineering: A, 2014, 619, 378- 383.
doi: 10.1016/j.msea.2014.09.096
23
MA Z , ZHAO H , HU X , et al. Influences of tensile pre-strain and bending pre-deflection on bending and tensile behaviors of an extruded AZ31B magnesium alloy[J]. Materials & Design, 2014, 64, 566- 572.
24
YAN Z , WANG D , HE X , et al. Deformation behaviors and cyclic strength assessment of AZ31B magnesium alloy based on steady ratcheting effect[J]. Materials Science and Engineering: A, 2018, 723, 212- 220.
doi: 10.1016/j.msea.2018.03.023
25
CALCAGNOTTO M , PONGE D , DEMIR E , et al. Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD[J]. Materials Science and Engineering: A, 2010, 527 (10): 2738- 2746.
2021, Vol. 49 
), 韦凯2, 杨旭静2, 齐军3
