PSI - Issue 81

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ScienceDirect

Procedia Structural Integrity 81 (2026) 156–161

© 2026 The Authors. Copy from the contract: 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 DMDP 2025 organizers Keywords: electroslag remelting; pulsed mode; cast structure; ingot; layer-by-layer formation 1. Introduction Electroslag remelting (ESR) is an effective method for producing high-quality ingots of various metals and alloys, as shown in the works of Halfa H. (2015), Holzgruber W. (2016). However, as the ingot size and the degree of alloying increase, obtaining ingots with a dense, homogeneous structure becomes more challenging (Cao H. et al. (2025), Kubin M. (2024), Bettoni P. et al (2014)). This is due to changes in heat transfer conditions (especially in the ingot's central zone), leading to an increase in the liquid metal pool volume, the formation of a coarse-grained structure, and the appearance of shrinkage and segregation defects. This significantly limits the capabilities of ESR for producing ingots of complex alloy systems — for example, precision alloys such as Kovar, Invar, Permendur, Permalloy, Supermalloy, and other Fe – Ni – Co, Fe – Ni, Fe – Co – V, and Ni – Fe – Mo systems. Abstract The results of a study on the characteristics of cast metal structure evolution in pulsed mode electroslag remelting (ESR) with layer-by-layer ingot formation are presented. Experiments were carried out on ingots of 85 – 220 mm diameter from carbon steels (S235JR, C22E) and a Fe – Ni – Co alloy (54Fe – 29Ni – 17Co). Remelting was performed in a chamber-type electroslag furnace in an argon atmosphere. Experiments were conducted under various conditions of the layer-by-layer ingot formation process. The resulting ingots were cut along their axis to study solidification patterns. It has been established that conducting ESR in a pulsed mode makes it possible to control the metal structure and produce ingots with a structure significantly finer than that obtained by conventional ESR. It is shown that during layer-by-layer formation, columnar crystals are localized within individual layers of metal and do not cross the boundaries between the deposited layers. A nearly linear relationship between the size of cast grains and the height of the deposited layer has been determined. The optimal structural refinement is achieved when the height of a single layer is maintained within the range of (0.1 – 0.5) × ingot diameter. For defect-free interlayer bonding the duration of melting pauses must be such that no more than 75 – 95% of the volume of the molten pool solidifies before the next portion is remelted. The study proposes principles for controlling cast structure in pulsed mode ESR, providing guidelines for producing ingots up to 220 mm in diameter with enhanced homogeneity. VIII International Conference “In - service Damage of Materials: Diagnostics and Prediction“ (DMDP 2025) Cast Structure Evolution in Pulsed Mode Electroslag Remelting Igor Protokovilov*, Vitalii Porokhonko, Victor Shapovalov, Farit Biktagirov E.O. Paton Electric Welding Institute, 11 Kazymyr Malevych Str., Kyiv, 03150, Ukraine

* Corresponding author. Tel.: +38-096-339-3336 E-mail address: lab38@paton.kiev.ua

2452-3216 © 2026 The Authors. Copy from the contract: 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 DMDP 2025 organizers 10.1016/j.prostr.2026.03.028