Nondestructive Measurement of Residual Strain in Connecting Rods Using Neutrons

Journal Article · Tue Oct 15 00:00:00 EDT 2019 · SAE International Journal of Materials and Manufacturing (Online)

DOI:https://doi.org/10.4271/05-12-03-0018· OSTI ID:1761743

Ikeda, Tomohiro ^[1]; Bunn, Jeffrey R. ^[2]; Fancher, Christopher ^[2]; Motani, Ryuta ^[1]; Matsuda, Hideki ^[1]; Okayama, Tatsuya ^[1]

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1. Honda R&D, Ltd. (Japan)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Increasing the strength of materials is effective in reducing weight and boosting structural part performance, but there are cases where the residual strain generated during the process of manufacturing of high-strength materials results in a decline of durability. It is therefore important to understand how the residual strain in a manufactured component changes due to processing conditions. In the case of a connecting rod, because the strain load on the connecting rod rib sections is high, it is necessary to clearly understand the distribution of strain in the ribs. However, because residual strain is generally measured by using X-ray diffractometers or strain gauges, measurements are limited to the surface layer of the parts. Neutron beams, however, have a higher penetration depth than X-rays, allowing for strain measurement in the bulk material. The research discussed within this article consists of nondestructive residual strain measurements in the interior of connecting rods using the Second Generation Neutron Residual Stress Mapping Facility (NRSF2) at Oak Ridge National Laboratory (ORNL), measuring the Fe (211) diffraction peak position of the ferrite phase. The interior strain distribution of the connecting rod, which was prepared under different manufacturing processes, was revealed. By the visualization of interior strains, clear understandings of differences in various processing conditions were obtained. In addition, it is known that the peak width, which is also obtained during measurement, is suggestive of the size of crystallites in the structure; however, the peak width can additionally be caused by microstresses and material dislocations.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1761743
• Journal Information: SAE International Journal of Materials and Manufacturing (Online), Journal Name: SAE International Journal of Materials and Manufacturing (Online) Journal Issue: 3 Vol. 12; ISSN 1946-3987
• Publisher: SAE International
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE