University of Oulu

Ali, M.; Porter, D.; Kömi, J.; Eissa, M.; El Faramawy, H.; Mattar, T. The Effect of Electroslag Remelting on the Microstructure and Mechanical Properties of CrNiMoWMnV Ultrahigh-Strength Steels. Metals 2020, 10, 262. https://doi.org/10.3390/met10020262

The effect of electroslag remelting on the microstructure and mechanical properties of CrNiMoWMnV ultrahigh-strength steels

Saved in:
Author: Ali, Mohammed1,2; Porter, David1; Kömi, Jukka1;
Organizations: 1Materials and Mechanical Engineering, Centre for Advanced Steels Research, University of Oulu, P.O. Box 4200, 90014 Oulu, Finland
2Steel Technology Department, Central Metallurgical Research and Development Institute (CMRDI), Helwan, Cairo 11421, Egypt
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 8.2 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2020041416468
Language: English
Published: Multidisciplinary Digital Publishing Institute, 2020
Publish Date: 2020-04-14
Description:

Abstract

The effect of electroslag remelting (ESR) with CaF2-based synthetic slag on the microstructure and mechanical properties of three as-quenched martensitic/martensitic-bainitic ultrahigh-strength steels with tensile strengths in the range of 1250–2000 MPa was investigated. Ingots were produced both without ESR, using induction furnace melting and casting, and with subsequent ESR. The cast ingots were forged at temperatures between 1100 and 950 °C and air cooled. Final microstructures were investigated using laser scanning confocal microscopy, field emission scanning electron microscopy, electron backscatter diffraction, electron probe microanalysis, X-ray diffraction, color etching, and micro-hardness measurements. Mechanical properties were investigated through measurement of hardness, tensile properties and Charpy-V impact toughness. The microstructures of the investigated steels were mainly auto-tempered martensite in addition to small fractions of retained austenite and bainite. Due to the consequences of subtle modifications in chemical composition, ESR had a considerable impact on the final microstructural features: Prior austenite grain, effective martensite grain, and lath sizes were refined by up to 52%, 38%, and 28%, respectively. Moreover, the 95th percentiles in the cumulative size distribution of the precipitates decreased by up to 18%. However, ESR had little, if any, the effect on microsegregation. The variable effects of ESR on mechanical properties and how they depend on the initial steel composition are discussed

see all

Series: Metals
ISSN: 2075-4701
ISSN-E: 2075-4701
ISSN-L: 2075-4701
Volume: 10
Issue: 2
Article number: 262
DOI: 10.3390/met10020262
OADOI: https://oadoi.org/10.3390/met10020262
Type of Publication: A1 Journal article – refereed
Field of Science: 216 Materials engineering
Subjects:
Funding: This research was funded by the Egyptian Ministry of Higher Education (Cultural Affairs and Missions Sector) and the APC was funded by Materials and Mechanical Engineering Department, University of Oulu, Oulu, Finland.
Copyright information: © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
  https://creativecommons.org/licenses/by/4.0/