Ultrafine elongated grain structure for enhanced cryogenic impact toughness of low-alloy steel

被引：0

作者：

Yang, Bo ^{[1
,2
]}

Fan, Kuanyuan ^{[1
,2
]}

Liu, Baoxi ^{[1
]}

Luo, Zhichao ^{[2
]}

Yin, Fuxing ^{[1
,2
]}

机构：

[1] Hebei Univ Technol, Sch Mat Sci & Engn, Tianjin Key Lab Mat Laminating Fabricat & Interfac, Tianjin 300130, Peoples R China

[2] Guangdong Acad Sci, Inst New Mat, Guangdong Prov Iron Matrix Composite Engn Res Ctr, Guangzhou 510650, Peoples R China

来源：

MATERIALS CHARACTERIZATION | 2025年 / 228卷

关键词：

Low-alloy steel; Bi-axial forging and rolling; Ultrafine elongated grain; Cryogenic impact toughness; Delamination toughening; C-MN STEEL; MECHANICAL-PROPERTIES; HIGH-STRENGTH; CLEAVAGE DELAMINATION; FRACTURE-BEHAVIOR; WARM DEFORMATION; MICROSTRUCTURE; TEXTURE; TEMPERATURE; MARTENSITE;

D O I：

10.1016/j.matchar.2025.115371

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

This study investigates the cryogenic impact toughness of low-alloy steels engineered via bi-axial forging and rolling, emphasizing the roles of ferrite volume fraction, microstructural refinement, and delamination-induced plasticity. Three steels were fabricated: F650 (forged at 650 degrees C), R730 (rolled at 730 degrees C), and R770 (rolled at 770 degrees C). Among them, R730 exhibited the highest impact toughness (252 J at -196 degrees C), outperforming R770 (134 J) and F650 (9 J). Unlike 9Ni steels, where high toughness stems from retained austenite, our results demonstrate that increasing the ferrite volume fraction and refining the grain structure significantly enhance impact toughness in the crack-arrester orientation. EBSD analyses revealed bamboo-like ultrafine elongated grains in the rolled steels, which promoted crack deflection and delamination, transforming the fracture mode to bending-dominated and enabling extensive plastic deformation. These findings demonstrate that optimizing ferrite fraction and grain morphology provides a robust route to achieve superior cryogenic toughness in lowalloy steels.

引用

页数：14

共 46 条

[1]

Ding R., Yao Y., Sun B., Et al., Chemical boundary engineering: a new route toward lean, ultrastrong yet ductile steels, Sci. Adv., 6, (2020)

[2]

Zhao J., Jiang Z., Thermomechanical processing of advanced high strength steels, Prog. Mater. Sci., 94, pp. 174-242, (2018)

[3]

Sun J., Wang H., Xu B., Et al., Making low-alloyed steel strong and tough by designing a dual-phase layered structure, Acta Mater., 227, (2022)

[4]

Kimura Y., Inoue T., Otani T., Et al., Upsizing high-strength fail-safe steel through warm tempforming, Mater. Sci. Eng. A, 819, (2021)

[5]

Liu L., Yu Q., Wang Z., Et al., Making ultrastrong steel tough by grain-boundary delamination, Science, 368, pp. 1347-1352, (2020)

[6]

He B.B., Hu B., Yen H.W., Et al., High dislocation density–induced large ductility in deformed and partitioned steels, Science, 357, pp. 1029-1032, (2017)

[7]

Song R., Ponge D., Raabe D., Mechanical properties of an ultrafine grained C–Mn steel processed by warm deformation and annealing, Acta Mater., 53, pp. 4881-4892, (2005)

[8]

Song R., Ponge D., Raabe D., Et al., Microstructure and crystallographic texture of an ultrafine grained C–Mn steel and their evolution during warm deformation and annealing, Acta Mater., 53, pp. 845-858, (2005)

[9]

Zhang H., Sun M., Liu Y., Et al., Ultrafine-grained dual-phase maraging steel with high strength and excellent cryogenic toughness, Acta Mater., 211, (2021)

[10]

Sakai T., Belyakov A., Kaibyshev R., Et al., Dynamic and post-dynamic recrystallization under hot, cold and severe plastic deformation conditions, Prog. Mater. Sci., 60, pp. 130-207, (2014)

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