Affiliation:
1. Alexander Dubcek University in Trenčín
2. Academy of Sciences of Czech Republic
3. Brno University of Technology
Abstract
The absorbed impact energy KV and the dynamic fracture toughness KId of the low-alloyed steel OCHN3MFA were measured in the respective temperature ranges 〈–40, 90〉 and 〈–60, –20〉 °C. The values of impact energy in the range of 〈14.1, 21.3〉 J were obtained using Charpy V-notch samples after subtracting parasitic energies (friction in bearings, etc.). All these values corresponded to an extended transition region since the temperature –40 °C was still higher than the lower shelf impact-energy (shear lips present) and the temperature 90 °C was lower than the upper shelf (only 20 % of ductile morphology). Dynamic fracture toughness was determined using Charpy V‑notch samples with fatigue pre-cracks. The related KId-values were obtained in the range 〈55.8, 77.5〉 MPa.m1/2. They were found to be valid linear-elastic fracture toughness and were somewhat higher than the previously reported static KIc-values. The study revealed that OCHN3MFA steel has sufficient resistance to dynamic fracture, particularly at low temperatures.
Publisher
Trans Tech Publications, Ltd.
Subject
Condensed Matter Physics,General Materials Science,Radiation
Reference6 articles.
1. J. Pokluda, I. Dlouhý, M. Kianicová, J. Čupera, J. Horníková, P. Šandera, Temperature Dependence of Fracture Characteristics of Variously Heat-Treated Grades of Ultra-High-Strength Steel: Experimental and Modelling, Materials 14 (2021) 5875.
2. ISO 148-1:2016 Metallic materials – Charpy pendulum impact test – Part 1: Test method, ASTM International, West Conshohocken, PA, 2016.
3. ISO 14556:2015, Metallic materials – Charpy V-notch pendulum impact test – Instrumented test method, ANSI, Washington, DC, 2015.
4. ASTM E 399-20, Standard test method for linear-elastic plane-strain fracture toughness KIc of metallic materials, in: Annual Book of ASTM-Standards, Philadelphia, Pennsylvania, 2020.
5. J. R. Rice, M. A. Johnson, The role of large crack tip geometry changes in plane strain fracture, in: M. F. Kanninen, W. F. Adler, A. R. Rosenfield, R. I. Jaffee (Eds.), Inelastic Behavior of Solids, McGraw-Hill, New York, 1970, pp.641-672.