PSI - Issue 71

Johnny Adukwu et al. / Procedia Structural Integrity 71 (2025) 295–301

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Fig. 4. (a) SPT curves for 4340 and 300 M steels (b) Variation in the strength with the hydrogen content

4. Conclusion This study demonstrates the behaviour of high strength steels (4340 and 300M) in a HE environment. Hydrogen diffusion tests indicate that 4340 has a much higher apparent diffusivity. On the other hand, shear punch test results showed a significant deterioration in the mechanical properties of 4340 compared to 300M. This difference in the HE response of the two steels can be attributed to the presence of different types of precipitates (mostly carbides) in them. The performance of aerospace martensitic steels in the presence of hydrogen indicates that hydrogen trapping within these steels could serve as a means to combat HE.

Acknowledgements

The research was done with partial support of Safran Landing Systems, Ajax, Ontario, Canada and the Natural Sciences and Engineering Research Council of Canada (NSERC).

References AMS 6257, 2007. Steel bars, forgings, and tubing, 1.6 Si-0.82 Cr-1.8 Ni-0.40 Mo-0.08 V (0.40-0.44 C), consumable electrode vacuum remelted and tempered. Warrendale: SAE International . ASTM F-519-13, 2013. Test for method for mechanical hydrogen embrittlement evaluation of plating/coating processes and service environments. ASTM International, West Conshohocken, PA. Bakhshi S., Mirak A., 2022. Textural development, martensite lath formation and mechanical properties variation of a super strength AISI4340 steel due to austenitization and tempering temperature changes. Materials Characterization 188, 111923. Bellemare J., Laliberte-Riverin S., Menard D., Brochu M., Sirois F., 2020. Subtleties behind hydrogen embrittlement of cadmium-plated 4340 steel revealed by thermal desorption spectroscopy and sustained-load tests. Metallurgical Material Transaction A 51, 3054 – 3065. Boellinghaus T., Steffens B., Rhode M., Shoales G., 2019. Hydrogen assisted stress corrosion cracking related material properties of service-applied landing gear ultra-high strength Steels. Corrosion Journal 75, 513 – 524. Figueroa D., Robinson M., 2010. Hydrogen transport and embrittlement in 300M and AerMet100 ultra high strength steels. Corrosion Science 52, 1593 – 1602. Guduru R., Darling K., Kishore R., Scattergood R., Koch C., Murt K.L., 2005. Evaluation of mechanical properties using shear-punch testing. Materials Science and Engineering A 395, 307 – 314. Kasana S., Sharma S., Pandey O., 2022. Influence of heat treatment (routes) on the microstructure and mechanical properties of 300M ultra high strength steel. Archives Civil and Mechanical Engineering 2022, 126.