Nanoindentation behavior and creep-induced cracking of long-term crept austenitic steel at 650 [1]C
Zhen Zhang1,2,3, Yu-hang Duan1, Shuai Wang1, Jin-shan Chen1,2, An-zhe Wang1,2, Xiang-yang Mao1,2, Yuan-ji Shi4, Jie Zhang5, Ming Liu6, Zheng-fei Hu7
1 School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, Jiangsu, China 2 Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing 211167, Jiangsu, China 3 Jiangsu Wind Power Engineering Technology Center, Nanjing 210023, Jiangsu, China 4 Nanjing Vocational University of Industry Technology, Nanjing 210023, Jiangsu, China 5 Baoshan Iron & Steel Co., Ltd., Shanghai 201900, China 6 Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350116, Fujian, China 7 School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
Nanoindentation behavior and creep-induced cracking of long-term crept austenitic steel at 650 [1]C
Zhen Zhang1,2,3, Yu-hang Duan1, Shuai Wang1, Jin-shan Chen1,2, An-zhe Wang1,2, Xiang-yang Mao1,2, Yuan-ji Shi4, Jie Zhang5, Ming Liu6, Zheng-fei Hu7
1 School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, Jiangsu, China 2 Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing 211167, Jiangsu, China 3 Jiangsu Wind Power Engineering Technology Center, Nanjing 210023, Jiangsu, China 4 Nanjing Vocational University of Industry Technology, Nanjing 210023, Jiangsu, China 5 Baoshan Iron & Steel Co., Ltd., Shanghai 201900, China 6 Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing, School of Mechanical Engineering and Automation, Fuzhou University, Fuzhou 350116, Fujian, China 7 School of Materials Science and Engineering, Tongji University, Shanghai 201804, China
摘要 The grain boundary (GB) damage of long-term crept HR3C (25Cr–20Ni–Nb–N) austenitic steel with solid solution state was investigated by nanoindentation test accompanied with in-situ electron back-scattered diffraction. The corresponding microstructure was characterized by scanning electron microscopy and transmission electron microscopy. Results show that the increase in nanoindentation hardness at the GBs and triple grain junctions may be related to the dislocation accumulation and carbide growth during the creep. Coarsened M23C6 and dislocations piling-up at the GB accelerate the nucleation and coalescence of creep cavity along the GB. The nanoindentation hardness in grains varies with orientation of the stress axis. The orientation difference of neighbor grains may induce local high geometrically necessary dislocation densities and strain gradients near the GB, consequently causing stress concentration and subsequent crack growth at specific GBs.
Abstract：The grain boundary (GB) damage of long-term crept HR3C (25Cr–20Ni–Nb–N) austenitic steel with solid solution state was investigated by nanoindentation test accompanied with in-situ electron back-scattered diffraction. The corresponding microstructure was characterized by scanning electron microscopy and transmission electron microscopy. Results show that the increase in nanoindentation hardness at the GBs and triple grain junctions may be related to the dislocation accumulation and carbide growth during the creep. Coarsened M23C6 and dislocations piling-up at the GB accelerate the nucleation and coalescence of creep cavity along the GB. The nanoindentation hardness in grains varies with orientation of the stress axis. The orientation difference of neighbor grains may induce local high geometrically necessary dislocation densities and strain gradients near the GB, consequently causing stress concentration and subsequent crack growth at specific GBs.
Zhen Zhang1,2,3, et al. Nanoindentation behavior and creep-induced cracking of long-term crept austenitic steel at 650 [1]C[J]. Journal of Iron and Steel Research International, 2024, 31(02): 464-474.
2024, Vol. 31 
