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Acta Metall Sin  2018, Vol. 54 Issue (7): 1031-1041    DOI: 10.11900/0412.1961.2017.00435
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Hydrogen Embrittlement of Intercritically AnnealedCold-Rolled 0.1C-5Mn Steel
Xiaoli ZHAO1,2, Yongjian ZHANG1, Chengwei SHAO1, Weijun HUI1(), Han DONG2
1 School of Mechanical, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044, China
2 Central Iron and Steel Research Institute, Beijing 100081, China
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Abstract  

Medium-Mn steel typically alloyed with (3%~10%)Mn (mass fraction) has recently regained significant interest as one of the most promising candidates for the third-generation automobile steel due to its excellent combination of ultra-high strength and ductility as well as relatively low material cost and industrial feasibility. Considering the ever increasing strength level as well as the comparatively high amount of reverted austenite (RA) of medium-Mn steel, special attention began to be given to its hydrogen embrittlement (HE) behavior for ensuring the safety service of components made of this kind of steel. However, the effect of RA on HE of medium-Mn steel has not been fully understood. For this purpose, the susceptibility to HE of a cold-rolled medium-Mn steel 0.1C-5Mn intercritically annealed at 650 ℃ for different time to obtain different amounts of RA was investigated by using electrochemical hydrogen charging, thermal desorption spectrometry (TDS), slow strain rate test (SSRT) and SEM. The results show that the annealed samples exhibit a dual-phase microstructure of reverted globular shaped RA and ferrite. The ultimate tensile strength (σb) increases while the yield strength decreases with increasing annealing time, and both the total elongation (δ) and the product of σb to δ (σb×δ) initially increase and then decrease with increasing annealing time. That is to say, an excellent combination of strength and ductility could be obtained when the tested steel was annealed at 650 ℃ for 10 min. However, the results of TDS and SSRT show that both the absorbed diffusible hydrogen concentration and the susceptibility to HE increase with increasing annealing time, and the latter is more significant. SEM analysis of the fracture surfaces of fractured samples revealed that the hydrogen-charged annealed sample was fractured to leave both dimples filled with grains and empty dimples while the uncharged annealed specimen was ductile fractured to leave only empty dimples. The dimples filled with grains were basically a brittle intergranular cracking occurring along the boundaries of RA and/or martensite (formerly RA) grains by the hydrogen-assisted cracking mechanism. It is thus concluded that the HE behavior of intercritically annealed cold-rolled medium-Mn steel is primarily controlled by both the amount and mechanical stability of RA.

Key words:  cold-rolled medium-Mn steel      susceptibility to hydrogen embrittlement      intercritical annealing      microstructure      austenite stability     
Received:  18 October 2017     
ZTFLH:  TG111  
  TG142  
Fund: Supported by Laboratory Program of Beijing Jiaotong University (No.16010211)

Cite this article: 

Xiaoli ZHAO, Yongjian ZHANG, Chengwei SHAO, Weijun HUI, Han DONG. Hydrogen Embrittlement of Intercritically AnnealedCold-Rolled 0.1C-5Mn Steel. Acta Metall Sin, 2018, 54(7): 1031-1041.

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2017.00435     OR     https://www.ams.org.cn/EN/Y2018/V54/I7/1031

Fig.1  TEM images of 0.1C-5Mn steel as-cold rolled (a) and after annealing at 650 ℃ for 10 min (b), 30 min (c) and 360 min (d) (RA—reverted austenite)
Fig.2  XRD spectra (a) and intercritical annealing time dependences of the austenite volume fraction and carbon content of austenite (b) in 0.1C-5Mn steel
Fig.3  Variations of tensile properties of the cold-rolled 0.1C-5Mn steel with annealing time at 650 ℃(a) ultimate tensile strength σb and yield strength σs(b) total elongation δ and σbδ
Fig.4  Hydrogen desorption rate curves of hydrogen-charging 0.1C-5Mn steel specimens (a) and hydrogen contents in the cold-rolled and intercritically annealed 0.1C-5Mn steel samples (b) before and after hydrogen-charging (Inset in Fig.4a shows the locally enlarged curve)
Fig.5  Engineering stress-strain curves of cold rolled and intercritically annealed 0.1C-5Mn steel samples before and after hydrogen-charging (a) and variations of hydrogen embrittlement index δloss with annealing time (b)
Fig.6  SEM fractographs of hydrogen-charged 0.1C-5Mn steel as-cold rolled (a) and after annealing at 650 ℃ for 10 min (b), 30 min (c) and 360 min (d) (Circles in the map represent brittle fracture zones)
Fig.7  SEM fractographs in crack initiation region of uncharged (a, c, e) and hydrogen-charged (b, d, f) 0.1C-5Mn steel as-cold rolled (a, b) and after annealing at 650 ℃ for 10 min (c, d) and 360 min (e, f) (Arrows in Figs.7d and f represent dimples filled with grain)
Annealing time Average size of filled grain in dimple Average size of reverted austenite
min μm μm
5 0.46±0.08 -
10 0.63±0.12 0.68±0.25
30 0.82±0.11 0.89±0.27
360 1.01±0.19 1.10±0.45
Table 1  Average sizes of filled grains in dimples of fractured specimens and average sizes of reverted austenites
Position in Fig.7f Mass fraction of Mn / % Position in Fig.7f Mass fraction of Mn / %
1 7.39 6 4.81
2 7.83 7 5.55
3 7.26 8 4.68
4 8.24 9 6.07
5 7.29 10 5.32
Mean value 7.60±0.42 Mean value 5.20±0.56
Table 2  EDS results of Mn content in fractographs of the hydrogen-charged annealed for 360 min sample shown in Fig.7f
Fig.8  Low (a) and locally high (b) magnified SEM images taken at the normal direction of the fractured hydrogen-charged 0.1C-5Mn steel annealed at 650 ℃ for 30 min, showing small voids initiated at the interface of reverted austenite and ferrite (Black arrows represent martensites and the white arrows represent ferrites)
Fig.9  Dislocation cells of the as-cold rolled 0.1C-5Mn steel
Fig.10  Variations of the volume fractions of RA after tensile test and transformed RA (a) and the ratio of dimples filled with grains (b) with annealing time
[1] Han Z Y, Zhang M D, Xu H F, et al.Research and application of high performance automobile steel[J]. Iron Steel, 2016, 51(2): 1(韩志勇, 张明达, 许海峰等. 高性能汽车钢组织性能特点及未来研发方向[J]. 钢铁, 2016, 51(2): 1)
[2] Lee Y K, Han J.Current opinion in medium manganese steel[J]. Mater. Sci. Technol., 2015, 31: 843
[3] Suh D W, Kim S J.Medium Mn transformation-induced plasticity steels: Recent progress and challenges[J]. Scr. Mater., 2017, 126: 63
[4] Cao W Q, Wang C, Shi J, et al.Microstructure and mechanical properties of Fe-0.2C-5Mn steel processed by ART-annealing[J]. Mater. Sci. Eng., 2011, A528: 6661
[5] Han J, Lee S J, Jung J G, et al.The effects of the initial martensite microstructure on the microstructure and tensile properties of intercritically annealed Fe-9Mn-0.05C steel[J]. Acta Mater., 2014, 78: 369
[6] Cai Z H, Ding H, Kamoutsi H, et al.Interplay between deformation behavior and mechanical properties of intercritically annealed and tempered medium-manganese transformation-induced plasticity steel[J]. Mater. Sci. Eng., 2016, A654: 359
[7] Shao C W, Hui W J, Zhang Y J, et al.Microstructure and mechanical properties of hot-rolled medium-Mn steel containing 3% aluminum[J]. Mater. Sci. Eng., 2017, A682: 45
[8] Li N, Shi J, Wang C Y, et al.Effect of annealing time on microstructure and mechanical properties of a cold rolled medium manganese steel[J]. Trans. Mater. Heat Treat., 2011, 32(8): 74(李楠, 时捷, 王存宇等. 两相区退火时间对冷轧中锰钢组织和力学性能的影响[J]. 材料热处理学报, 2011, 32(8): 74)
[9] Arlazarov A, Gouné M, Bouaziz O, et al.Evolution of microstructure and mechanical properties of medium Mn steels during double annealing[J]. Mater. Sci. Eng., 2012, A542: 31
[10] Yin H X, Zhao A M, Zhao Z Z, et al.Effect of annealing time on the microstructure and mechanical properties of a cold rolled medium-manganese TRIP steel[J]. J. Univ. Sci. Technol. Beijing, 2013, 35: 1158(尹鸿祥, 赵爱民, 赵征志等. 退火时间对冷轧中锰TRIP钢组织和力学性能的影响[J]. 北京科技大学学报, 2013, 35: 1158)
[11] Wang C, Cao W Q, Yan Y, et al.Influences of austenization temperature and annealing time on duplex ultrafine microstructure and mechanical properties of medium Mn steel[J]. J. Iron Steel Res. Int., 2015, 22: 42.
[12] Lee S, Shin S, Kwon M, et al.Tensile properties of medium Mn steel with a bimodal UFG α+γ and coarse δ-ferrite microstructure[J]. Metall. Mater. Trans., 2017, 48A: 1678
[13] Ronevich J A, De Cooman B C, Speer J G, et al. Hydrogen effects in prestrained transformation induced plasticity steel[J]. Metall. Mater. Trans., 2012, 43A: 2293
[14] Ryu J H, Chun Y S, Lee C S, et al.Effect of deformation on hydrogen trapping and effusion in TRIP-assisted steel[J]. Acta Mater., 2012, 60: 4085
[15] Han J, Nam J H, Lee Y K.The mechanism of hydrogen embrittlement in intercritically annealed medium Mn TRIP steel[J]. Acta Mater., 2016, 113: 1.
[16] Wang M M, Tasan C C, Koyama M, et al.Enhancing hydrogen embrittlement resistance of lath martensite by introducing nano-films of interlath austenite[J]. Metall. Mater. Trans., 2015, 46A: 3797
[17] Van Dijk N H, Butt A M, Zhao L, et al. Thermal stability of retained austenite in TRIP steels studied by synchrotron X-ray diffraction during cooling[J]. Acta Mater., 2005, 53: 5439
[18] Wang C, Shi J, Wang C Y, et al.Development of ultrafine lamellar ferrite and austenite duplex structure in 0.2C5Mn steel during ART-annealing[J]. ISIJ Int., 2011, 51: 651
[19] Lee S, Lee S J, De Cooman B C. Austenite stability of ultrafine-grained transformation-induced plasticity steel with Mn partitioning[J]. Scr. Mater., 2011, 65: 225
[20] Takai K, Watanuki R.Hydrogen in trapping states innocuous to environmental degradation of high-strength steels[J]. ISIJ Int., 2003, 43: 520.
[21] Wang M Q, Dong H, Hui W J, et al.Effect of hydrogen on notch tensile strength of high strength steel[J]. Trans. Mater. Heat Treat., 2006, 27(4): 57(王毛球, 董瀚, 惠卫军等. 氢对高强度钢缺口拉伸强度的影响[J]. 材料热处理学报, 2006, 27(4): 57)
[22] Escobar D P, Depover T, Duprez L, et al.Combined thermal desorption spectroscopy, differential scanning calorimetry, scanning electron microscopy and X-ray diffraction study of hydrogen trapping in cold deformed TRIP steel[J]. Acta Mater, 2012, 60: 2593
[23] Hui W J, Zhang Y J, Zhao X L, et al.Influence of cold deformation and annealing on hydrogen embrittlement of cold hardening bainitic steel for high strength bolts[J]. Mater. Sci. Eng., 2016, A662: 528
[24] Nagumo M, Takai K, Okuda N. Nature of hydrogen trapping sites in steels induced by plastic deformation [J]. J. Alloys Compd., 1999, 293-295: 310
[25] Suzuki N, Ishii N, Tuchida Y.Diffusible hydrogen behavior in pre-strained high strength steel[J]. Tetsu Hagané, 1994, 80: 855(鈴木信一, 石井伸幸, 土田豊. 高張力鋼の拡散性水素の挙動に及ぼす塑性歪の影響[J]. 鉄と鋼, 1994, 80: 855)
[26] Zhao J W, Jiang Z Y, Lee C S.Effects of tungsten on the hydrogen embrittlement behaviour of microalloyed steels[J]. Corros. Sci., 2014, 82: 380
[27] Lee S M, Park I J, Jung J G, et al.The effect of Si on hydrogen embrittlement of Fe-18Mn-0.6C-xSi twinning-induced plasticity steels[J]. Acta Mater., 2016, 103: 264
[28] Shi J, Jun H, Wang C, et al.Ultrafine grained duplex structure developed by ART-annealing in cold rolled medium-Mn steels[J]. J. Iron Steel Res. Int., 2014, 21: 208
[29] Zhan W, Cao W Q, Hu J, et al.Intercritical rolling induced ultrafine lamellar structure and enhanced mechanical properties of medium-Mn steel[J]. J. Iron Steel Res. Int., 2014, 21: 551
[30] Takagi S, Toji Y, Yoshino M, et al.Hydrogen embrittlement resistance evaluation of ultra high strength steel sheets for automobiles[J]. ISIJ Int., 2012, 52: 316
[31] Matsuoka S, Homma N, Tanaka H, et al.Effect of hydrogen on the tensile properties of 900 MPa-class JIS-SCM435 low-alloy-steel for use in storage cylinder of hydrogen station[J]. J. Jpn. Inst. Met., 2006, 70: 1002(松岡三郎, 本間紳浩, 田中裕之等. 900 MPa級低合金鋼SCM435の引張特性に及ぼす水素の影響[J]. 日本金属学会誌, 2006, 70: 1002)
[32] Michler T, Naumann J.Microstructural aspects upon hydrogen environment embrittlement of various bcc steels[J]. Int. J. Hydrogen Energy, 2010, 35: 821
[33] Chen J, Li C J, Zhang S H.Hydrogen embrittlement of cold drawn ferrite +martensite dual-phase steel[J]. J. Univ. Sci. Technol. Beijing, 1990, 12: 339(陈俊, 李承基, 章守华. 冷拔变形(F+M)型双相钢的氢脆[J]. 北京科技大学学报, 1990, 12: 339)
[34] Li X F, Wang Y F, Zhang P, et al.Effect of pre-strain on hydrogen embrittlement of high strength steels[J]. Mater. Sci. Eng., 2014, A616: 116
[35] Zhu X, Zhang K, Li W, et al.Effect of retained austenite stability and morphology on the hydrogen embrittlement susceptibility in quenching and partitioning treated steels[J]. Mater. Sci. Eng., 2016, A658: 400
[36] Chan S L I, Lee H L, Yang J R. Effect of retained austenite on the hydrogen content and effective diffusivity of martensitic structure[J]. Metall. Trans., 1991, 22A: 2579
[37] Sun Y W, Chen J Z, Liu J.Study on hydrogen embrittlement susceptibility of 1000 MPa grade 0Cr16Ni5Mo steel[J]. Acta Metall. Sin., 2015, 51: 1315(孙永伟, 陈继志, 刘军. 1000 MPa级0Cr16Ni5Mo钢的氢脆敏感性研究[J]. 金属学报, 2015, 51: 1315)
[38] Xu P G, Yin J, Zhang S Y.Tensile deformation behavior of hydrogen charged ultrahigh strength steel studied by in situ neutron diffraction[J]. Acta Metall. Sin., 2015, 51: 1297(徐平光, 殷匠, 张书彦. 充氢超高强度钢拉伸变形的原位中子衍射研究[J]. 金属学报, 2015, 51: 1297)
[39] Wang C, Xu H F, Huang C X, et al.Evolution of ART-annealed microstructure and partition behavior of manganese in medium manganese steel[J]. J. Iron Steel Res. Int., 2016, 28(4): 38(王昌, 徐海峰, 黄崇湘等. 中锰钢逆相变退火组织的演变及锰的配分行为[J]. 钢铁研究学报, 2016, 28(4): 38)
[40] Oudriss A, Creus J, Bouhattate J, et al.Grain size and grain-boundary effects on diffusion and trapping of hydrogen in pure nickel[J]. Acta Mater., 2012, 60: 6814
[41] Bai Y, Momotani Y, Chen M C, et al.Effect of grain refinement on hydrogen embrittlement behaviors of high-Mn TWIP steel[J]. Mater. Sci. Eng., 2016, A651: 935
[42] Hui W J, Dong H, Weng Y Q, et al.Delayed fracture behavior of ultrafine grained high strength steel[J]. Acta Metall. Sin., 2004, 40: 561(惠卫军, 董瀚, 翁宇庆等. 超细晶粒超强度钢的延迟断裂行为[J]. 金属学报, 2004, 40: 561)
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