Effect of temperature on microstructure and residual stresses induced by surface treatments in Inconel 718 SPF

SURFACE & COATINGS TECHNOLOGY

卷:344

Article

Telang, Abhishek¹  Gili, Amrinder S.²  Mannava, Seetha R.¹  Qian, Dong³  Vasudevan, Vijay K.¹ 

[1] Univ Cincinnati, Dept Mech & Mat Engn, 501B ERC,2901 Woodside Dr, Cincinnati, OH 45221 USA

[2] AK Steel Res Ctr, Middletown, OH USA

[3] Univ Texas Dallas, Dept Mech Engn, Richardson, TX 75083 USA

关键词: Residual stress;    Microstructure;    X-ray diffraction;    Superalloys;    Laser shock peening;    Surface treatments;   

DOI  :  10.1016/j.surfcoat.2018.02.094

来源: Elsevier

【 摘 要 】

In this study, Inconel 718 (IN718SPF) samples were treated with three surface modification techniques: laser shock peening (LSP), cavitation shotless peening (CSP) and ultrasonic nanocrystalline surface modification (UNSM). Subsequently, these samples were exposed to temperatures between 550 degrees C-650 degrees C for different time intervals. Residual stresses on the sample surfaces were measured using XRD to compare the thermal relaxation behavior of samples treated with different surface treatments. The results show that surface compressive residual stresses induced by all three surface treatments are stable at high temperatures after initial relaxation. Further, TEM micrographs were obtained from surface treated samples that were exposed to 550 degrees C for 5 min and 24 h. A comparison of microstructures before and after thermal exposure is presented. The study quantifies activation enthalpy for residual stresses relaxation in LSP, CSP and UNSM treated IN718SPF and a relaxation mechanism is proposed.

【 授权许可】

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