Effect of heat treatment on the microstructure and fatigue behaviour of AISI 4130 steel

0578079 - ÚFM 2024 RIV SK eng J - Journal Article
Poloprudský, Jakub - Chlupová, Alice - Šulák, Ivo - Obrtlík, Karel
Effect of heat treatment on the microstructure and fatigue behaviour of AISI 4130 steel.
Kovové materiály. Roč. 61, č. 6 (2023), s. 401-407. ISSN 0023-432X. E-ISSN 1338-4252
R&D Projects: GA TA ČR CK02000025
Institutional support: RVO:68081723
Keywords : medium carbon steel * heat treatment * fatigue life * microstructure * scanning electron microscopy
OECD category: Materials engineering
Impact factor: 0.7, year: 2022
Method of publishing: Open access
http://www.kovmat.sav.sk/article.php?rr=61&cc=6&ss=401

AISI 4130 steel is widely used in the aircraft industry, mainly for frame structures. It is
a medium carbon low-alloyed (25CrMo4) steel predetermined for precipitation of carbides in
the microstructure during heat treatment. Six different heat treatments were applied to study
the effect of the resulting microstructure (ferritic-pearlitic in a normalised state or martensitic
with carbides in a hardened state) on the fatigue life of AISI 4130. Tension-tension cycling
under force control was used to determine the S-N curve of flat specimens with a central
circular notch. The best fatigue properties were achieved for the material state HT125, i.e.,
hardened & tempered to 125 ksi (863 MPa), exhibiting the maximum stress at a fatigue limit
of 225 MPa, which is approximately 5–15 % better compared to the rest of the applied heat
treatments. Microstructural investigations using scanning electron microscopy explained the
acquired fatigue life results of AISI 4130 concerning different heat-treated conditions.
Permanent Link: https://hdl.handle.net/11104/0347116