Microscopic examination of striation spacing during ductile crack growth in Fe-3wt%Si single-crystalline thin plates in air and hydrogen

被引：1

作者：

Huynh, Thanh Thuong ^{[1
,2
]}

Hamada, Shigeru ^{[3
]}

Tsuzaki, Kaneaki ^{[3
,4
,5
]}

Noguchi, Hiroshi ^{[3
]}

机构：

[1] Can Tho Univ, Dept Mech Engn, Campus 2, Ninh Kieu Dist, Can Tho, Vietnam

[2] Kyushu Univ, Grad Sch Engn, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[3] Kyushu Univ, Dept Mech Engn, Nishi Ku, 744 Motooka, Fukuoka 8190395, Japan

[4] Natl Inst Mat Sci, Res Ctr Struct Mat, 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan

[5] Kyoto Univ, Elements Strategy Initiat Struct Mat ESISM, Sakyo Ku, Kyoto 6068501, Japan

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2021年 / 802卷

关键词：

Ductile crack growth; Hydrogen; Steel; Delayed fracture; Plastic strain; Dislocation; Single crystal; ENVIRONMENTALLY ASSISTED CRACKING; STRESS; DEFORMATION; PROPAGATION; PLASTICITY; FIELDS;

D O I：

10.1016/j.msea.2020.140652

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Microscopic features of crack growth in thin plates of single-crystalline Fe-3wt%Si alloy in both air and hydrogen environments were investigated by electron channeling contrast imaging (ECCI), electron backscattering diffraction (EBSD), as well as scanning electron microscopy fractography. The goal was to elucidate the discontinuous crack growth as well as the constant unit distance of crack extension (striation spacing). Centercracked specimens were tested under a sustained load in a hydrogen environment, while they were under continuous stretching in the air environment. The following results were obtained. (1) Striation is formed by extensive slips emitted from the crack tip, mainly contributed from specific (1 (1) over bar2)[(1) over bar 11] and ((1) over bar 12)[(1) over bar1 (1) over bar] slip systems. The discontinuous crack growth is mainly caused by interaction of the crack and (1 (1) over bar2)[(1) over bar 11] and ((1) over bar 12) [(1) over bar1 (1) over bar] slip bands/cell walls formed ahead of the crack tip. These slip bands/cells show that the spacing between slip bands/cells is constant and independent of the crack length. Hence, the striation spacing is the same as that of the slip bands/cells ahead of the crack tip. (2) Hydrogen may affect the slip behavior by reducing the spacing between slip bands/cells ahead of the crack tip compared to that in the air environment.

引用

页数：10

共 28 条

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