PSI - Issue 71

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ScienceDirect

Procedia Structural Integrity 71 (2025) 74–81

5 th International Structural Integrity Conference & Exhibition (SICE 2024) Investigating the Behavior of Su-263 Under Increasing Loads Using Small Punch Creep Testing Pramod Ravindra Kushwaha*, Atul Ramesh Ballal, Seelam Rajasekhar Reddy Department of Metallurgical & Materials Engineering, Visvesvaraya National Institute of Technology, Nagpur 440010, India Abstract Small punch creep (SPC) testing has the potential as an alternative to conventional uniaxial creep testing when limited amount of material is available. This method of creep testing can be used to find the remaining life of an in-service components. This paper investigates the creep life of superalloy Su-263 using small punch creep test. SPC tests were conducted on 0.5 mm thick Su-263 specimens at test temperature of 650 °C at the nominal load values of 650 N, 700 N, and 750 N. The punch displacement versus time curve showed three distinct stages and showed a two-slope behaviour wherein the hump was found after particular time duration for each of the tested loads. The appearance of hump was observed to occur early as the load was increased from 650 N to 750 N. Transition in fracture mode of SPC specimens from plastic intergranular at low loads to highly brittle intergranular fracture at high loads was observed. The fraction of time elapsed in percentage of life with increasing load was calculated and the same has been explained with a graphical representation. The fracture mechanism has been neatly depicted using fractography of SPC tested samples. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers

Keywords: Small punch creep (SPC); Su-263; constant load; fractography; * Corresponding author. Tel.: +91-9096985329 E-mail address: kushwahapramod2298@gmail.com

1. Introduction Su-263 is an advanced high-temperature alloy comprised, primarily, of nickel, chromium, and molybdenum. It has garnered significant attention in industries such as aerospace and power generation due to its exceptional creep resistance properties. Su-263 is widely used in stationary components of gas turbines such as in combustion chambers, casings, bearing housings (Srinivas et al. 1995, Chandra et al. 2018, and Manonukul et al. 2002) etc typically operating at a temperature 600 °C to 750 °C. Creep is a time dependent plastic deformation phenomenon under constant stress at elevated temperatures, profoundly impacting the structural integrity of materials. Creep life represents the duration until failure under

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers 10.1016/j.prostr.2025.08.011