Effects of processing routes on room temperature tensile strength and elongation for Inconel 718 Yung-Ta Chen a , An-Chou Yeh a, ⁎, Ming-Yen Li b , Shih-Ming Kuo b a Department of Material Science and Engineering, National Tsing-Hua University, Taiwan, ROC b New Materials Research & Development Department, China Steel Corporation, Taiwan, ROC HIGHLIGHTS • The amount of pre-aging δ is critical in influencing the strength of IN718. • Hot rolling above the δ solvus plus di- rect aging can result desired tensile property. • A good balance of ultra-high tensile strength and moderate elongation can be achieved. • Simple processing route for high strength IN718 has been designed in this study. GRAPHICAL ABSTRACT abstract article info Article history: Received 9 August 2016 Received in revised form 17 January 2017 Accepted 23 January 2017 Available online 24 January 2017 For oil and gas industrial applications, materials of deep downhole drilling components are required to possess tensile strength over 1400 MPa at room temperature. The present study demonstrates that processing design for Inconel 718 can widen the spectrum of its mechanical properties to meet the demand for ultra-high room temperature tensile strength. The range of room temperature tensile properties achieved in this study include tensile strength of 1785 MPa in one end of spectrum, and large tensile strain over 40% in the other end. Furthermore, a well-balanced tensile property of 1430 MPa with 18% tensile strain can be achieved by minimizing the formation of pre-aging δ precipitates through direct aging process. The strengthening mechanisms and the trade-off between tensile strength and ductility have been investigated and discussed. © 2017 Elsevier Ltd. All rights reserved. Keywords: Superalloys Tensile strength Tensile strain Precipitation strengthening Strain hardening Materials and Design 119 (2017) 235–243 ⁎ Corresponding author. E-mail address: yehac@mx.nthu.edu.tw (A.-C. Yeh). http://dx.doi.org/10.1016/j.matdes.2017.01.069 0264-1275/© 2017 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Materials and Design journal homepage: www.elsevier.com/locate/matdes