Effect of Coiling Temperatures on Microstructures and Mechanical Properties of Industrial Trial-produced Ferritic High Hole Expansion Steel

BAI Yichao; CUI Lei; LIU Yang; LU Qianqian; MA Cong; Alexander Gramlich; WANG Xiaohui; HU Bin

doi:10.3969/j.issn.1674-6457.2025.12.009

PDF(16106 KB)

Journal of Netshape Forming Engineering ›› 2025, Vol. 17 ›› Issue (12) : 85-94. DOI: 10.3969/j.issn.1674-6457.2025.12.009

Advanced Aerospace Manufacturing Technology

Effect of Coiling Temperatures on Microstructures and Mechanical Properties of Industrial Trial-produced Ferritic High Hole Expansion Steel

BAI Yichao¹, CUI Lei², LIU Yang², LU Qianqian², MA Cong², Alexander Gramlich³, WANG Xiaohui^4,*, HU Bin^1,*

Author information +

History +

Abstract

To address the issue of insufficient performance margin in the hole expansion capacity of high hole expansion steel, the work aims to systematically investigate the effect of coiling temperatures on the tensile and hole expansion properties of four industrially trial-produced ferrite-based high hole expansion steels subject to different coiling processes, thus identifying the prevailing challenges in enhancing the hole expansion performance. The mechanical properties and microstructure were characterized with a universal testing machine, a microhardness tester (HV-1002), a field emission scanning electron microscope (ZEISS GeminiSEM 300), an electron probe microanalyzer (JXA-8530F Plus), and an Auger electron spectrometer (AES)-electron backscatter diffraction (EBSD) system (PHI 710). It was found that high hole expansion steel, when coiled at 630 ℃, exhibited peak yield and tensile strengths of 722 MPa and 798 MPa, respectively. However, at this stage, coarse pearlite precipitated at the thickness center of the hot-rolled sheet due to C/Mn segregation. During deformation, the non-uniform strain distribution between the center and near-surface regions made the material prone to centerline delamination cracking, thereby reducing the hole expansion ratio to 34.1%. Lowering the coiling temperature to 500-550 ℃ or raising it to 700 ℃ could suppress the formation of pearlite at the center of the hot-rolled sheet and improve the hole expansion ratio. However, because the coiling temperature deviated from the nose precipitation temperature of vanadium carbide (VC), the strength decreased and the yield and tensile strengths fell within the ranges of 530-640 MPa and 620-730 MPa, respectively. In conclusion, when the coiling temperature is 630 ℃/700 ℃, the segregation of C at the sheet center thickness promotes the formation of pearlite/cementite microstructure, resulting in increased hardness difference between the center and edge regions, which leads to cracking. Additionally, when the coiling temperature increases to 630 ℃, the yield strength and tensile strength reach their maximum values of 722 MPa and 798 MPa, respectively. To enhance the hole expansion ratio of high-strength ferritic hole expansion steel, it is necessary to mitigate the C/Mn segregation at the center of the slab. This improvement ensures that when coiling is performed near the nose temperature for vanadium carbide (VC) precipitation, the formation of pearlite at the sheet center can be effectively suppressed.

Key words

ferritic high hole expansion steel / strength / central delamination cracking / segregation / pearlite

Cite this article

EndNote

Ris (Procite)

Bibtex

Download Citations

BAI Yichao, CUI Lei, LIU Yang, LU Qianqian, MA Cong, Alexander Gramlich, WANG Xiaohui, HU Bin. Effect of Coiling Temperatures on Microstructures and Mechanical Properties of Industrial Trial-produced Ferritic High Hole Expansion Steel[J]. Journal of Netshape Forming Engineering. 2025, 17(12): 85-94 https://doi.org/10.3969/j.issn.1674-6457.2025.12.009

References

[1] CZERWINSKI F.Current Trends in Automotive Lightweighting Strategies and Materials[J]. Materials, 2021, 14(21): 6631.
[2] BOUAZIZ O, ZUROB H, HUANG M X.Driving Force and Logic of Development of Advanced High Strength Steels for Automotive Applications[J]. Steel Research International, 2013, 84(10): 937-947.
[3] ROBINSON A L, TAUB A I, KEOLEIAN G A.Fuel Efficiency Drives the Auto Industry to Reduce Vehicle Weight[J]. MRS Bulletin, 2019, 44(12): 920-923.
[4] JOOST W J.Reducing Vehicle Weight and Improving U.S. Energy Efficiency Using Integrated Computational Materials Engineering[J]. JOM, 2012, 64(9): 1032-1038.
[5] HOU L C, WANG Y P, ZHENG Y H, et al.The Impact of Vehicle Ownership on Carbon Emissions in the Transportation Sector[J]. Sustainability, 2022, 14(19): 12657.
[6] NODER J, GUTIERREZ J E, ZHUMAGULOV A, et al.A Comparative Evaluation of Third-Generation Advanced High-Strength Steels for Automotive Forming and Crash Applications[J]. Materials, 2021, 14(17): 4970.
[7] RAMACHANDRAN D C, MIDAWI A R H, SHOJAEE M, et al. A Comprehensive Evaluation of Tempering Kinetics on 3rd Generation Advanced High Strength Steels[J]. Materialia, 2022, 26: 101644.
[8] NABEEL M, ALBA M, KARASEV A, et al.Characterization of Inclusions in 3rd Generation Advanced High-Strength Steels[J]. Metallurgical and Materials Transactions B, 2019, 50(4): 1674-1685.
[9] BHARGAVA M, TEWARI A, MISHRA S K.Forming Limit Diagram of Advanced High Strength Steels (AHSS) Based on Strain-Path Diagram[J]. Materials & Design, 2015, 85: 149-155.
[10] THANOS B A C, THEMELIS N J. Materials and Energy Recovery at Six European MBT Plants[J]. Waste Management, 2022, 141: 79-91.
[11] ARNDT M, DUCHOSLAV J, PREIS K, et al.Nanoscale Surface Analysis on Second Generation Advanced High Strength Steel after Hot Dip Galvanizing[J]. Analytical and Bioanalytical Chemistry, 2013, 405(22): 7119-7132.
[12] GU G H, SEO M H, SUH D W, et al.Observation of Multi-Scale Damage Evolution in Transformation-Induced Plasticity Steel under Bending Condition[J]. Materials Today Communications, 2023, 34: 105291.
[13] 巢成新, 于强, 李秋. 汽车用先进高强钢本构模型与韧性断裂模型研究进展[J]. 精密成形工程, 2024, 16(1): 77-86.
CHAO C X, YU Q, LI Q.Research Progress on Constitutive Model and Ductile Fracture Model of Advanced High Strength Steel for Automotive Applications[J]. Journal of Netshape Forming Engineering, 2024, 16(1): 77-86.
[14] KASHIMA T, HASHIMOTO S, MUKAI Y.780 N/mm² Grade Hot-Rolled High-Strength Steel Sheet for Automotive Suspension System[J]. JSAE Review, 2003, 24(1): 81-86.
[15] PLOSILA P, KESTI V, HANNULA J, et al.A Comparison between Tensile and Hole Expansion Properties in 800 MPa Tensile Strength Grade Hot-Rolled Steels[J]. Materials Today Communications, 2024, 40: 109521.
[16] BARNWAL V K, LEE S Y, YOON S Y, et al.Fracture Characteristics of Advanced High Strength Steels during Hole Expansion Test[J]. International Journal of Fracture, 2020, 224(2): 217-233.
[17] LIANG J W, YANG D P, CHEN X F, et al.Hole Expansion Behavior of 1 100 MPa Grade Dual-Phase Steel with Superior Stretch-Flangeability[J]. Materials Today Communications, 2024, 39: 108929.
[18] LI W, VITTORIETTI M, JONGBLOED G, et al.Microstructure-Property Relation and Machine Learning Prediction of Hole Expansion Capacity of High-Strength Steels[J]. Journal of Materials Science, 2021, 56(34): 19228-19243.
[19] MISRA R D K, THOMPSON S W, HYLTON T A, et al. Microstructures of Hot-Rolled High-Strength Steels with Significant Differences in Edge Formability[J]. Metallurgical and Materials Transactions A, 2001, 32(13): 745-760.
[20] NGUYEN D T, TONG V C.A Numerical and Experimental Study on the Hold-Edge Conditions and Hole-Expansion Ratio of Hole-Blanking and Hole-Expansion Tests for Ferrite Bainite Steel (FB590) Sheets[J]. Ironmaking & Steelmaking, 2021, 48(8): 986-994.
[21] FUNAKAWA Y, SHIOZAKI T, TOMITA K, et al.Development of High Strength Hot-Rolled Sheet Steel Consisting of Ferrite and Nanometer-Sized Carbides[J]. ISIJ International, 2004, 44(11): 1945-1951.
[22] LIU S C, DONG H K, LI Y B, et al.Flash Annealing Enables 1 GPa Nanoprecipitate-Strengthened “NANOHITEN” Ferritic Steels[J]. Materials Science and Engineering: A, 2022, 861: 144364.
[23] 国家市场监督管理总局, 国家标准化管理委员会. 汽车用高强度热连轧钢板及钢带第2部分:高扩孔钢: GB/T 20887.2—2022[S]. 北京: 中国标准出版社, 2022.
State Administration for Market Regulation, Standardization Administration of the People’s Republic of China. Continuously Hot Rolled High Strength Steel Sheet and Strip for Automobile: Part 2: High Hole Expansion Steel: GB/T 20887.2—2022[S]. Beijing: Standards Press of China, 2022.
[24] OKAMOTO R, BORGENSTAM A, ÅGREN J.Interphase Precipitation in Niobium-Microalloyed Steels[J]. Acta Materialia, 2010, 58(14): 4783-4790.
[25] JI F Q, LI C N, TANG S, et al.Microstructural Characteristics with Various Finish Rolling Temperature and Low Temperature Toughness in Hot Rolled Nb-Ti Ferritic Steel[J]. ISIJ International, 2016, 56(4): 602-609.
[26] PEI X H, LIU Z Y, WEI J, et al.Microstructure and Properties of a Low Carbon Ti-V Microalloyed Steel[J]. Journal of Wuhan University of Technology-Mater Sci Ed, 2018, 33(6): 1491-1495.
[27] ZHANG Y J, SHINBO K, OHMURA T, et al.Randomization of Ferrite/Austenite Orientation Relationship and Resultant Hardness Increment by Nitrogen Addition in Vanadium-Microalloyed Low Carbon Steels Strengthened by Interphase Precipitation[J]. ISIJ International, 2018, 58(3): 542-550.
[28] LIANG W, YUAN Q, ZHANG Q X, et al.Study on Fracture Mechanism and Microstructural Evolution in 780 MPa Grade FB Steel with a High Hole Expanding Ratio[J]. Journal of Materials Engineering and Performance, 2021, 30(3): 1641-1651.
[29] SON Y I, LEE Y K, PARK K T, et al.Ultrafine Grained Ferrite-Martensite Dual Phase Steels Fabricated via Equal Channel Angular Pressing: Microstructure and Tensile Properties[J]. Acta Materialia, 2005, 53(11): 3125-3134.
[30] 戚齐. 高强热轧高扩孔钢组织及性能研究[D]. 沈阳: 东北大学, 2020.
QI Q.Research on Microstructure and Properties of High Hole-expansion Steel Manufactured by Hot Rolling[D]. Shenyang: Northeastern University, 2020.
[31] 曹锐. 相间析出强化高强高扩孔钢的组织性能研究[D]. 北京: 北京科技大学, 2023: 59-63.
CAO R Investigation on the Microstructure and Mechanical Properties of High Strength and High Hole-Expansion Steels Fabricated via Interphase Precipitation[D]. Beijing: University of Science and Technology Beijing, 2023: 59-63.
[32] PAUL S K.A Critical Review on Hole Expansion Ratio[J]. Materialia, 2020, 9: 100566.
[33] 薛启河, 李正团, 刘磊, 等. 卷取温度对800 MPa级高扩孔钢组织性能的影响[J]. 河北冶金, 2025(10): 36-41.
XUE Q H, LI Z T, LIU L, et al.Effect of Coiling Temperatures on Microstructure and Properties of 800 MPa Grade High Hole Expansion Steel[J]. Hebei Metallurgy, 2025(10): 36-41.
[34] 国家市场监督管理总局, 国家标准化管理委员会. 金属材料薄板和薄带扩孔试验方法: GB/T 24524— 021[S]. 北京: 中国标准出版社, 2021.
State Administration for Market Regulation, Standardization Administration of the People’s Republic of China. Metallic Materials-Sheet and Strip-Hole Expanding Test: GB/T 24524—2021[S]. Beijing: Standards Press of China, 2021.
[35] HASHEMI S G, EGHBALI B.Analysis of the Formation Conditions and Characteristics of Interphase and Random Vanadium Precipitation in a Low-Carbon Steel during Isothermal Heat Treatment[J]. International Journal of Minerals, Metallurgy, and Materials, 2018, 25(3): 339-349.
[36] GONG P, LIU X G, RIJKENBERG A, et al.The Effect of Molybdenum on Interphase Precipitation and Microstructures in Microalloyed Steels Containing Titanium and Vanadium[J]. Acta Materialia, 2018, 161: 374-387.
[37] NOUSIAINEN O, HANNULA J, SAUKKO S, et al.Precipitation Behavior of Novel 1 GPa Ferritic Advanced High Strength Steels[J]. Materials Characterization, 2023, 201: 112944.
[38] ZHANG Y J, MIYAMOTO G, FURUHARA T.Enhanced Hardening by Multiple Microalloying in Low Carbon Ferritic Steels with Interphase Precipitation[J]. Scripta Materialia, 2022, 212: 114558.
[39] MIYAMOTO G, HORI R, POORGANJI B, et al.Interphase Precipitation of VC and Resultant Hardening in V-Added Medium Carbon Steels[J]. ISIJ International, 2011, 51(10): 1733-1739.

Funding

Beijing Municipal Natural Science Foundation, China (2242048); Yunnan Key Research and Development Program Materials Genomics Project (202403AA080013)