An attempt to correlate the change of the swept area (Delta A/b(2)) by mobile dislocations with the mechanism of the fatigue crack propagation rate (da/dN) in environmental hydrogen: Application in Inconel 690

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	An attempt to correlate the change of the swept area (Delta A/b(2)) by mobile dislocations with the mechanism of the fatigue crack propagation rate (da/dN) in environmental hydrogen: Application in Inconel 690
	Luo, XH; Habashi, M; Luo, XH (reprint author), Chinese Acad Sci, Inst Met Res, CAS Key Lab Nucl Mat & Safety Assessment, Shenyang, Liaoning, Peoples R China.
刊名	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
	2018-01-02
卷号	709 页码:349-357
关键词	Stress-corrosion Cracking Austenitic Stainless-steel Alloy-600 Nickel Water
ISSN号	0921-5093
英文摘要	The thermally activated dislocation motion due to plastic deformation in Inconel 690 has been carried out by performing tensile tests in air and in environmental hydrogen using the strain relaxation technique. The results show that the variation of - delta(Delta A/b(2)) or ln(V-H/V-Air) with epsilon(p) depends on the nickel content in the alloy and the microstructure, and generally increases with increasing Ni% for low value of epsilon(p) (tensile test). The maximum increase in the rate change was observed for the austenized and aged microstructure. On the other hand, fatigue crack propagation rate (da/dN) has been measured in the same environments. An attempt has been carried out to correlate the rate change - delta(Delta A/b(2)) or ln(V-H/V-Air) with the variation of (da/dN)(H) against (da/dN)(Air) (the variation of Omega) and has shown that for the austenized and aged microstructure, Omega is higher than those for stress relieved or only aged at 700 degrees C. These results are similar to those obtained by the thermal activation parameter - delta (Delta A/b(2)) or the ratio ln(V-H/V-Air). The maximum values of - delta (Delta A/b(2)) and Omega are obtained when the density of precipitates on the grain boundaries is higher than that in the matrix. In this case, intergranular fractures with fin slip lines features on the grain surfaces were observed. Finally, in the presence of environmental hydrogen, about the fatigue crack propagation rate, two relationships were established and expressed as: 1) in stages I and II: (Delta epsilon(p)/2) = Theta Delta K + Gamma and 2) only in stage II: (da/dN)(II) = c(II) (Delta epsilon(p) / 2)(lambda), where lambda approximate to m = 2, the power factor in Paris' law.; The thermally activated dislocation motion due to plastic deformation in Inconel 690 has been carried out by performing tensile tests in air and in environmental hydrogen using the strain relaxation technique. The results show that the variation of - delta(Delta A/b(2)) or ln(V-H/V-Air) with epsilon(p) depends on the nickel content in the alloy and the microstructure, and generally increases with increasing Ni% for low value of epsilon(p) (tensile test). The maximum increase in the rate change was observed for the austenized and aged microstructure. On the other hand, fatigue crack propagation rate (da/dN) has been measured in the same environments. An attempt has been carried out to correlate the rate change - delta(Delta A/b(2)) or ln(V-H/V-Air) with the variation of (da/dN)(H) against (da/dN)(Air) (the variation of Omega) and has shown that for the austenized and aged microstructure, Omega is higher than those for stress relieved or only aged at 700 degrees C. These results are similar to those obtained by the thermal activation parameter - delta (Delta A/b(2)) or the ratio ln(V-H/V-Air). The maximum values of - delta (Delta A/b(2)) and Omega are obtained when the density of precipitates on the grain boundaries is higher than that in the matrix. In this case, intergranular fractures with fin slip lines features on the grain surfaces were observed. Finally, in the presence of environmental hydrogen, about the fatigue crack propagation rate, two relationships were established and expressed as: 1) in stages I and II: (Delta epsilon(p)/2) = Theta Delta K + Gamma and 2) only in stage II: (da/dN)(II) = c(II) (Delta epsilon(p) / 2)(lambda), where lambda approximate to m = 2, the power factor in Paris' law.
学科主题	Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering
语种	英语
公开日期	2018-06-05
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/79594]
专题	金属研究所_中国科学院金属研究所
通讯作者	Luo, XH (reprint author), Chinese Acad Sci, Inst Met Res, CAS Key Lab Nucl Mat & Safety Assessment, Shenyang, Liaoning, Peoples R China.
推荐引用方式 GB/T 7714	Luo, XH,Habashi, M,Luo, XH . An attempt to correlate the change of the swept area (Delta A/b(2)) by mobile dislocations with the mechanism of the fatigue crack propagation rate (da/dN) in environmental hydrogen: Application in Inconel 690[J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,2018,709:349-357.
APA	Luo, XH,Habashi, M,&Luo, XH .(2018).An attempt to correlate the change of the swept area (Delta A/b(2)) by mobile dislocations with the mechanism of the fatigue crack propagation rate (da/dN) in environmental hydrogen: Application in Inconel 690.MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING,709,349-357.
MLA	Luo, XH,et al."An attempt to correlate the change of the swept area (Delta A/b(2)) by mobile dislocations with the mechanism of the fatigue crack propagation rate (da/dN) in environmental hydrogen: Application in Inconel 690".MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 709(2018):349-357.