Effect of the Martensite Lath on Toughness of 20CrNi2Mo Steel

doi:10.11901/1005.3093.2017.301

Chinese Journal of Materials Research

2018, Vol. 32

Issue (4): 290-300 DOI: 10.11901/1005.3093.2017.301

ARTICLES

Current Issue | Archive | Adv Search

Effect of the Martensite Lath on Toughness of 20CrNi2Mo Steel

Yemao LU^1,^2,^3,⁴, Yilong LIANG^1,^2,^3,⁴(

), Shaolei LONG^1,^2,^3,⁴, Cunhong YIN^2,^3,⁴, Ming YANG^1,^2,^3,⁴

1 College of Materials and Metallurgy, University of Guizhou, Guiyang 550025, China
2 Key Laboratory for Material Structure and Strength of Guizhou Province, Guiyang 550025, China
3 Guizhou Key Laboratory of High Performance Metal Structure and Manufacture Technology, Guiyang 550025,China
4 National Local Co-construction Engineering Laboratory for High Performance Metal Structure Material and Manufacture Technology, Guiyang 550025, China

Cite this article:

Yemao LU, Yilong LIANG, Shaolei LONG, Cunhong YIN, Ming YANG. Effect of the Martensite Lath on Toughness of 20CrNi2Mo Steel. Chinese Journal of Materials Research, 2018, 32(4): 290-300.

Download:

HTML

PDF(9688KB)
Export: BibTeX | EndNote (RIS)

Abstract

The impact toughness and fracture toughness were studied for 20CrNi2Mo steel quenching at different temperatures and the hierarchical microstructures obtained were investigated by OM, SEM, EBSD and TEM. Results showed that materials quenching at 1200℃ had best toughness in which the fracture toughness and impact absorption energy increased 43.58% and 27.78%, respectively. The size of prior austenite grain (d_r), packet (d_p) and block (d_b) was increased with the increase of quenching temperature, while the martensite lath (d_l) was decreased slightly with the coarsen of prior austenite grain. It was proved that the effective control unit of toughness for the tested steel was martensite lathes by crack propagation path analyzing and the statistic of dimple size combined with the Hall-Petch formula. In addition, the difference of plastic deformation was declared by EBSD and the relationship between fracture toughness and impact toughness during crack propagation process was calculated.

Key words: metallic materials lath martnesite steel control unit impact toughness fracture toughness deformation energy

Received: 09 May 2017

Fund: Supported by National Natural Science Foundation of China (Nos. 51461006 & 51671060)

	Service

	E-mail this article
	Add to citation manager
	E-mail Alert
	RSS
	（）
	Articles by authors
	Yemao LU
	Yilong LIANG
	Shaolei LONG
	Cunhong YIN
	Ming YANG

URL:

https://www.cjmr.org/EN/10.11901/1005.3093.2017.301 OR https://www.cjmr.org/EN/Y2018/V32/I4/290

Table 1 Chemical composition of 20CrNi2Mo (%, mass fraction)

Fig.1 Schematic maps of heat treatment for 20CrNi2Mo steel

Fig.2 Standard samples of Chapy U-notch specimen and fracture toughness sample

Fig.3 Relationship between J and △a in different austenitizing temperatures (a) 900℃, (b) 1000℃, (c) 1100℃, (d) 1200℃

Fig.4 Relationship between toughness and the prior austenite grain size at different quenching temperatures

Fig.5 OM (a)、SEM (b)、EBSD (c)、TEM (d) microstructure of 20CrNi2Mo martensitic steel quenched at different temperatures

Table 2 Multi-level microstructure characteristics of the 20CrNi2Mo steel

Fig.6 Cracks extending propagating path in growth zone at austenitizing temperatures of 900℃ and 1200℃

Table 3 Percent of the length (L' ) that cracks crossing packets

Fig.7 Relationship between the mean dimple sizes and austenitizing temperatures (a) dimple on impact sample quenched at 900℃ (b) dimple on impact sample quenched at 1200℃ (c) dimple on fracture toughness sample quenched at 900℃ (d) dimple on fracture toughness sample quenched at 1200℃

Fig.8 Relationship between the mean dimple sizes and the multi-level microstructure in 20CrNi2Mo steel (a) prior austenite grain size (d_r), (b) packet size (d_p), (c) block size (d_b), (d) lath width (d_l)

Fig.9 Relationship between the toughness (CUN and J_IC) and the multi-level microstructures in 20CrNi2Mo steel (a) prior austenite grain size (d_r), (b) packet size (d_p), (c) block width (d_b), (d) lath width (d_l)

Table 4 CUN and J_IC and 2δ_ICin different Austenitizing temperature

Fig.10 High strain region in different sample in crack tip

Table 5 Proportion of low angle boundary in different samples

Fig.11 Low angle boundary distribution near the cracks (a) impact sample quenched at 900℃ (b) impact sample quenched at 1200℃ (c) fracture toughness sample quenched at 900℃ (d) fracture toughness sample quenched at 1200℃

Fig.12 Strain contouring in crack tip (a) fracture toughness sample quenched at 900℃, (b) fracture toughness sample quenched at 1200℃

Fig.13 Relationship between High strain region width and strain

[1]	Han J, Silva A K D, Ponge D, et al. The effects of prior austenite grain boundaries and microstructural morphology on the impact toughness of intercritically annealed medium Mn steel[J]. Acta Mater. 2017, 122: 199
[2]	Kuzmina M, Ponge D, Raabe D.Grain boundary segregation engineering and austenite reversion turn embrittlement into toughness: Example of a 9 wt.% medium Mn steel[J]. Acta Mater. 2015, 86: 182
[3]	Koyama M, Zhang Z, Wang M, et al.Bone-like crack resistance in hierarchical metastable nanolaminate steels[J]. Science. 2017, 355(6329): 1055
[4]	Song S H, Faulkner R G, Flewitt P E J. Effect of boron on phosphorus-induced temper embrittlement[J]. J. Mater. Sci. 1999, 34(22): 5549
[5]	Grange R A.Strengthening steel by austenite grain refinement[J]. ASM-Trans. 1966, 59(1)
[6]	Krauss G. Martensite in steel: strength and structure[J]. Jater. Sci. Eng. A.1999, s 273-275(99): 40
[7]	Roberts M J.Effect of transformation substructure on the strength and toughness of Fe-Mn alloys[J]. Metall Trans. 1970, 1(12): 3287
[8]	Zong B W, Song Y W.Effect of the effective grains in ultra-high steel on its toughness[J]. Met. Sci. Technol., 1985, (4): 43(钟炳文, 宋宇文. 超高强度钢中有效晶粒对韧性的影响[J]. 材料科学与工艺, 1985(4): 43)
[9]	Lan H F, Du L X, Li Q, et al.Improvement of strength-toughness combination in austempered low carbon bainitic steel: The key role of refining prior austenite grain size[J]. J. Alloys Compd. 2017, 710: 702
[10]	S. Morito, H. Tanaka, R. Konishi, et al., The morphology and crystallography of lath martensite in Fe-C alloys[J], Acta Mater. 2003, 51(6): 1789
[11]	Zhang X L, Zhuang C J, Ji L K.Characteristic parameters of high grade pipeline steels and Its relationship with toughness[J]. J. Mater. Eng., 2008, (8): 3(张小立, 庄传晶, 吉玲康等. 高钢级管线钢的特征参量及其与强韧性的关系[J]. 材料工程, 2006, (8): 3)
[12]	Luo Z, Shen J, Su H, Ding Y, Yang C, Zhu X.Effect of Substructure on Toughness of Lath Martensite/Bainite Mixed Structure in Low-Carbon Steels[J], J. Iron. Steel Res. Int. 2010, 17(11): 40
[13]	Wang C F, Wang M Q, Shi J, et al.Effect of microstructural refinement on the toughness of low carbon martensitic steel[J]. Scr.Mater, 2008, 58(6): 492
[14]	Morito S, Huang X, Furuhara T, et al.The morphology and crystallography of lath martensite in alloy steels[J]. Acta Mater. 2006, 54(19): 5323
[15]	Long S L, Liang Y L, Jiang Y, et al.Effect of quenching temperature on martensite multi-level microstructures and properties of strength and toughness in 20CrNi2Mo steel[J]. Mater. Sci. Eng. A. 2016, 676: 38
[16]	Cui Q F, Hui H, Wang H Y, et al.Applicability of empirical correlations between impact energy and fracture toughness for Q345R steel[J]. Materials for Mechanical Engineering, 2015, 39(12): 84(崔庆丰, 惠虎, 王昊旸等. 冲击功与断裂韧度经验关系式对Q345R 钢的适用性[J]. 机械工程材料, 2015, 39(12): 84)
[17]	Xu C G, Yu G.A discussion on the relationship between impact toughness and fracture toughness[J]. Acta Aeronaut. Astronaut. Sin. 1990, 11(4): 182(许昌淦, 余刚. 冲击韧性与断裂韧性间关系的探讨[J]. 航空学报, 1990, 11(4): 182)
[18]	Zhao J W, Zhang W, Zou D N.Effect of Quenching temperature and cooling manner on the property of the high speed steel roll[J]. Foundry Technology, 2005
[19]	Ma P, Li Q, Tang G Q, et al.Carbide dissolution and grain growth behavior of Cr5 steel used as cold work roller during austenitizing. Mater. Mech. Eng. 2010, 34(6): 21(马坪, 李倩, 唐志国等. 冷轧工作辊用Cr5钢奥氏体化时碳化物的溶解及晶粒长大行为[J]. 机械工程材料, 2010, 34(6): 21)
[20]	Tan Y H, Ma Y X.Martensite New Morphology[M]. Beijing: Metallurgical Industry Press, 2013(谭玉华, 马跃新. 马氏体新形态学 [M]. 北京: 冶金工业出版社, 2013)
[21]	Xu Z Y.Effect of lath martensite morphology on the mechanical properties of steel[J], Heat Hreat, 2009, 24(3): 1(徐祖耀. 条状马氏体形态对钢力学性质的影响[J]. 热处理, 2009, 24(3): 1)
[22]	Zheng C Q.A Preliminary Study on Micromechanics of Ductile fracture and Application[M], Xi'an: Northwestern ploytechnical university press, 1988(郑长卿. 韧性断裂细观力学的初步研究及其应用[M]. 西安: 西北工业大学出版社, 1988)
[23]	Liang Y L, Long S L, Xu P W, et al.The important role of martensite laths to fracture toughness for the ductile fracture controlled by the strain in EA4T axle steel[J]. Mater. Sci. Eng. A. 2017, 695: 154
[24]	Liang Y L, Lei M, Zhong S H, et al.The relationship between fracture toughness and notch toughness, tensile ductilities in lath martensite steel[J]. Acta Metall. Sin, 1998, (09): 950(梁益龙, 雷旻, 钟蜀辉等. 板条马氏体钢的断裂韧性与缺口韧性、拉伸塑性的关系[J], 金属学报, 1998, (09): 950)
[25]	Hu J, Lin D L.A study of microstructural evolution of coarse-grained Ni-42Al alloy during superplastic deformation using EBSD analysis[J]. Iron Steel, 2008, 29(04): 91(胡静, 林栋樑. 大晶粒Ni-42Al合金超塑变形中组织演变EBSD分析[J]. 材料热处理学报, 2008, 29(04): 91)
[26]	Liang X k, Sun X J, Liu Q Y, et al. Mechanism s of plastic deformation of ultrafine grained steel at different temperatures[J]. Iron Steel, 2004, (11): 5(梁小凯, 孙新军, 刘清友等. 超细晶钢在不同温度下塑性变形机制的研究[J]. 钢铁, 2004, (11): 5)

[1]	MAO Jianjun, FU Tong, PAN Hucheng, TENG Changqing, ZHANG Wei, XIE Dongsheng, WU Lu. Kr Ions Irradiation Damage Behavior of AlNbMoZrB Refractory High-entropy Alloy[J]. 材料研究学报, 2023, 37(9): 641-648.
[2]	SONG Lifang, YAN Jiahao, ZHANG Diankang, XUE Cheng, XIA Huiyun, NIU Yanhui. Carbon Dioxide Adsorption Capacity of Alkali-metal Cation Dopped MIL125[J]. 材料研究学报, 2023, 37(9): 649-654.
[3]	ZHAO Zhengxiang, LIAO Luhai, XU Fanghong, ZHANG Wei, LI Jingyuan. Hot Deformation Behavior and Microstructue Evolution of Super Austenitic Stainless Steel 24Cr-22Ni-7Mo-0.4N[J]. 材料研究学报, 2023, 37(9): 655-667.
[4]	SHAO Hongmei, CUI Yong, XU Wendi, ZHANG Wei, SHEN Xiaoyi, ZHAI Yuchun. Template-free Hydrothermal Preparation and Adsorption Capacity of Hollow Spherical AlOOH[J]. 材料研究学报, 2023, 37(9): 675-684.
[5]	XING Dingqin, TU Jian, LUO Sen, ZHOU Zhiming. Effect of Different C Contents on Microstructure and Properties of VCoNi Medium-entropy Alloys[J]. 材料研究学报, 2023, 37(9): 685-696.
[6]	OUYANG Kangxin, ZHOU Da, YANG Yufan, ZHANG Lei. Microstructure and Tensile Properties of Mg-Y-Er-Ni Alloy with Long Period Stacking Ordered Phases[J]. 材料研究学报, 2023, 37(9): 697-705.
[7]	XU Lijun, ZHENG Ce, FENG Xiaohui, HUANG Qiuyan, LI Yingju, YANG Yuansheng. Effects of Directional Recrystallization on Microstructure and Superelastic Property of Hot-rolled Cu71Al18Mn11 Alloy[J]. 材料研究学报, 2023, 37(8): 571-580.
[8]	XIONG Shiqi, LIU Enze, TAN Zheng, NING Likui, TONG Jian, ZHENG Zhi, LI Haiying. Effect of Solution Heat Treatment on Microstructure of DZ125L Superalloy with Low Segregation[J]. 材料研究学报, 2023, 37(8): 603-613.
[9]	LIU Jihao, CHI Hongxiao, WU Huibin, MA Dangshen, ZHOU Jian, XU Huixia. Heat Treatment Related Microstructure Evolution and Low Hardness Issue of Spray Forming M3 High Speed Steel[J]. 材料研究学报, 2023, 37(8): 625-632.
[10]	YOU Baodong, ZHU Mingwei, YANG Pengju, HE Jie. Research Progress in Preparation of Porous Metal Materials by Alloy Phase Separation[J]. 材料研究学报, 2023, 37(8): 561-570.
[11]	REN Fuyan, OUYANG Erming. Photocatalytic Degradation of Tetracycline Hydrochloride by g-C₃N₄ Modified Bi₂O₃[J]. 材料研究学报, 2023, 37(8): 633-640.
[12]	WANG Hao, CUI Junjun, ZHAO Mingjiu. Recrystallization and Grain Growth Behavior for Strip and Foil of Ni-based Superalloy GH3536[J]. 材料研究学报, 2023, 37(7): 535-542.
[13]	LIU Mingzhu, FAN Rao, ZHANG Xiaoyu, MA Zeyuan, LIANG Chengyang, CAO Ying, GENG Shitong, LI Ling. Effect of Photoanode Film Thickness of SnO₂ as Scattering Layer on the Photovoltaic Performance of Quantum Dot Dye-sensitized Solar Cells[J]. 材料研究学报, 2023, 37(7): 554-560.
[14]	QIN Heyong, LI Zhentuan, ZHAO Guangpu, ZHANG Wenyun, ZHANG Xiaomin. Effect of Solution Temperature on Mechanical Properties and γ' Phase of GH4742 Superalloy[J]. 材料研究学报, 2023, 37(7): 502-510.
[15]	GUO Fei, ZHENG Chengwu, WANG Pei, LI Dianzhong. Effect of Rare Earth Elements on Austenite-Ferrite Phase Transformation Kinetics of Low Carbon Steels[J]. 材料研究学报, 2023, 37(7): 495-501.

No Suggested Reading articles found!

Viewed

Full text

Abstract

Cited

Shared

Discussed