Effect of surface characteristics on strain distribution in air- bending

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Effect of surface characteristics on strain distribution in air- bending

KAIJALAINEN Antti, POKKA Aki-Petteri, JASKARI Matias, HUUKI Juha, HINTSALA Tommi, KÖMI Jukka

Abstract. This study is a continuation of previous studies; therefore, the idea is to determine the influence of surface roughness and hardness on the bendability of a UHSS grade, and it is investigated with 3-point bending tests, utilizing Digital Image Correlation (DIC) for measuring the strain distributions on the outer curvature. Investigated bending samples of a 4 mm thick commercial bainitic-martensitic steel sheet were tested in different surface conditions: (1) as- rolled, (2) dry electropolished, (3) ultrasonic burnishing and (4) a combination of dry electropolishing and ultrasonic burnishing. Ultrasonic burnishing increased the surface hardness and decreased the surface roughness. Bending results showed that smoother surface did not lead to improved bending angles and higher hardness in the subsurface decreased the bending capacity, i.e., reduced the maximum bending angle and critical strain.

Keywords
Roughness, Hardness, Bendability, DIC, Ultra-High Strength Steel

Published online 9/15/2024, 8 pages
Copyright © 2024 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: KAIJALAINEN Antti, POKKA Aki-Petteri, JASKARI Matias, HUUKI Juha, HINTSALA Tommi, KÖMI Jukka, Effect of surface characteristics on strain distribution in air- bending, Materials Research Proceedings, Vol. 44, pp 350-357, 2024

DOI: https://doi.org/10.21741/9781644903254-37

The article was published as article 37 of the book Metal Forming 2024

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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