PSI - Issue 57

Available online at www.sciencedirect.com Available online at www.sciencedirect.com Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 57 (2024) 420–427 Structural Integrity Procedia 00 (2023) 000–000 Structural Integrity Procedia 00 (2023) 000–000

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© 2024 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 the scientific committee of the Fatigue Design 2023 organizers Abstract Ultra high strength steels provide opportunities for reduced-weight designs since they have higher tensile and fatigue strengths than the conventional mild steel grades. For typical applications such as telescopic cranes, tippers, chassis, and agricultural machinery, lower weight leads to lower fuel consumption and better road homologation. Before the start of their service life, steel components must be machined to their final shape as they are supplied in standardized shapes and sizes. Mechanical and thermal cutting strategies invoke various physical phenomena within the cut material a ff ecting the in-use properties. The objective of this study is to quantify the e ff ect of hole-making processes and edge-preparation on fatigue performance of ultra high strength steels. A series of fatigue experiments were conducted on steel grades with yield strengths from 700 to 960 MPa using axially loaded coupon samples with a hole manufactured by punching and laser cutting. Fatigue performance is compared to the detail categories provided by design standards. Additional tests under four-point bending loading were conducted to focus on flat edges machined by laser cutting and milling. Especially at high-cycle and infinite-fatigue lives, tested grades were superior to the typical design curves when the holes were punched with low clearance or laser cut. c 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2023 organizers. Keywords: fatigue; ultra-high strength steels; hole-making; punching; laser cutting Fatigue Design 2023 (FatDes 2023) Hole-making and cutting e ff ects on fatigue performance of ultra high strength steels Okan Yılmaz a, ∗ , Dennis van Hoecke a a ArcelorMittal Global R & D Gent - OCAS N.V., Pres. J.F. Kennedylaan 3, 9060 Zelzate, Belgium Abstract Ultra high strength steels provide opportunities for reduced-weight designs since they have higher tensile and fatigue strengths than the conventional mild steel grades. For typical applications such as telescopic cranes, tippers, chassis, and agricultural machinery, lower weight leads to lower fuel consumption and better road homologation. Before the start of their service life, steel components must be machined to their final shape as they are supplied in standardized shapes and sizes. Mechanical and thermal cutting strategies invoke various physical phenomena within the cut material a ff ecting the in-use properties. The objective of this study is to quantify the e ff ect of hole-making processes and edge-preparation on fatigue performance of ultra high strength steels. A series of fatigue experiments were conducted on steel grades with yield strengths from 700 to 960 MPa using axially loaded coupon samples with a hole manufactured by punching and laser cutting. Fatigue performance is compared to the detail categories provided by design standards. Additional tests under four-point bending loading were conducted to focus on flat edges machined by laser cutting and milling. Especially at high-cycle and infinite-fatigue lives, tested grades were superior to the typical design curves when the holes were punched with low clearance or laser cut. c 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2023 organizers. Keywords: fatigue; ultra-high strength steels; hole-making; punching; laser cutting Fatigue Design 2023 (FatDes 2023) Hole-making and cutting e ff ects on fatigue performance of ultra high strength steels Okan Yılmaz a, ∗ , Dennis van Hoecke a a ArcelorMittal Global R & D Gent - OCAS N.V., Pres. J.F. Kennedylaan 3, 9060 Zelzate, Belgium

Nomenclature Nomenclature

R Load ratio c Punching clearance FAT Stress range in MPa at two million cycles for a specific detail category m Slope term for a specific detail category S-N Stress vs. life R Load ratio c Punching clearance FAT Stress range in MPa at two million cycles for a specific detail category m Slope term for a specific detail category S-N Stress vs. life

2452-3216 © 2024 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 the scientific committee of the Fatigue Design 2023 organizers 10.1016/j.prostr.2024.03.045 ∗ Corresponding author. Tel.: + 32-477-030917. E-mail address: okan.yilmaz@arcelormittal.com 2210-7843 c 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2023 organizers. ∗ Corresponding author. Tel.: + 32-477-030917. E-mail address: okan.yilmaz@arcelormittal.com 2210-7843 c 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http: // creativecommons.org / licenses / by-nc-nd / 4.0 / ) Peer-review under responsibility of the scientific committee of the Fatigue Design 2023 organizers.