Influence of grain inhomogeneity and precipitates on the stress rupture properties of Inconel 718 superalloy fabricated by selective laser melting

被引：36

作者：

Zhang, Shuya ^{[1
,2
]}

Lin, Xin ^{[1
,2
]}

Wang, Lilin ^{[1
,2
]}

Yu, Xiaobin ^{[1
,2
]}

Yang, Haiou ^{[1
,2
]}

Lei, Liming ^{[3
]}

Huang, Weidong ^{[1
,2
]}

机构：

[1] Northwestern Polytech Univ, State Key Lab Solidificat Proc, 127 Youyixilu, Xian 710072, Shaanxi, Peoples R China

[2] Northwestern Polytech Univ, Key Lab Met High Performance Addit Mfg & Innovat, MIIT China, 127 Youyixilu, Xian 710072, Shaanxi, Peoples R China

[3] AECC Commercial Aircraft Engine Co Ltd, 3998 South Lianhua Rd, Shanghai 200241, Peoples R China

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2021年 / 803卷

基金：

国家重点研发计划;

关键词：

Selective laser melting; Inconel; 718 gamma'' precipitate; Grain inhomogeneity; Stress rupture properties; MECHANICAL-PROPERTIES; HEAT-TREATMENT; CREEP DEFORMATION; MICROSTRUCTURE; BEHAVIOR; ALLOY; PARAMETERS; SIZE;

D O I：

10.1016/j.msea.2020.140702

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

Optimizing the microstructure to enhance the high temperature stress rupture properties of Inconel 718 (IN718) alloy fabricated via selective laser melting (SLM) is an urgent issue. In this study, SLM-built IN718 specimens were heat-treated with hot isostatic pressing, solution and aging treatment, and their microstructure and high temperature stress rupture properties were investigated, focusing on the influence of grain structure and precipitates. The results show that the coarsening of gamma '' precipitate with the aging time at 720 degrees C follows the LifshitzSlyozov-Wagner theory. As the gamma '' precipitate size increases, the rupture life gradually increases, area reduction gradually decreases, and the uniform elongation first increases and then decreases. Furthermore, a wide distribution of grain size results in the fine grains regions with much higher geometrically necessary dislocations compared with coarse grain regions during deformation. Hence, the micro-cracks preferentially initiate and propagate along fine-grain boundary. The main deformation mechanisms of specimens aged at 720 degrees C for 4 h (HSA4) and 8 h (HSA8) with the small gamma '' precipitate are dislocation slipping and micro-twinning mode during stress rupture test, while those of specimen aged at 720 degrees C for 32 h (HSA32) with relatively large gamma '' precipitate are dislocation slipping and isolated faulting mode. The HSA8 specimen with the best comprehensive stress rupture properties has the average life of 130 h and uniform elongation of 7.5%, meeting the standard specification for wrought IN718. Finally, some potential strategies for further improving the stress rupture properties of SLM-built IN718 were proposed by comparing to forged-IN718.

引用

页数：11

共 46 条

[1] Microstructures and mechanical behavior of Inconel 718 fabricated by selective laser melting [J].

Amato, K. N. ;

Gaytan, S. M. ;

Murr, L. E. ;

Martinez, E. ;

Shindo, P. W. ;

Hernandez, J. ;

Collins, S. ;

Medina, F. .

ACTA MATERIALIA, 2012, 60 (05) :2229-2239

[2] Simulation of creep cavity growth in Inconel 718 alloy [J].

Ankit, Kumar ;

Prasad, Nishtala .

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2011, 528 (12) :4209-4216

[3]

ANSELL GS, 1959, T AM I MIN MET ENG, V215, P838

[4]

Boyd R.B.N., 1971, ACTA MAT, V12, P1379

[5] Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD [J].

Calcagnotto, Marion ;

Ponge, Dirk ;

Demir, Eralp ;

Raabe, Dierk .

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2010, 527 (10-11) :2738-2746

[6] Investigations of γ′, γ" and δ precipitates in heat-treated Inconel 718 alloy fabricated by selective laser melting [J].

Cao, G. H. ;

Sun, T. Y. ;

Wang, C. H. ;

Li, Xing ;

Liu, M. ;

Zhang, Z. X. ;

Hu, P. F. ;

Russell, A. M. ;

Schneider, R. ;

Gerthsen, D. ;

Zhou, Z. J. ;

Li, C. P. ;

Chen, G. F. .

MATERIALS CHARACTERIZATION, 2018, 136 :398-406

[7]

Chaturvedi M.C., 1987, MAT SCI ENG, V7

[8] THE EFFECT OF GRAIN-BOUNDARY PRECIPITATES ON THE CREEP-BEHAVIOR OF INCONEL 718 [J].

CHEN, W ;

CHATURVEDI, MC .

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 1994, 183 (1-2) :81-89

[9]

CHEN W, 1993, CAN METALL QUART, V32, P363

[10]

Chen W., 1997, ACTA MAT, V7, P2746

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