Effects of Test Temperature on Low Cycle Fatigue Behaviors in Large Mold Steel

• Published in: Metals and materials international Vol. 27; no. 7; pp. 2292 - 2299
• Main Authors: Shin, Jong-Ho, Lee, Jehyun
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01-07-2021; Springer Nature B.V; 대한금속·재료학회
• Subjects: Amplitudes; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cyclic loads; Ductility tests; Empirical equations; Engineering Thermodynamics; Fatigue tests; Heat and Mass Transfer; Image transmission; Injection molding; Low cycle fatigue; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metal fatigue; Metallic Materials; Molds; Processes; Recovery; Solid Mechanics; Steel; Strain rate; Temperature; 재료공학; Mold steel; M; C carbide; Low cycle fatigue (LCF); Dislocation recovery; Transmission electron microscope
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-020-00760-3

A mold steel for plastic injection was subjected to low cycle fatigue (LCF) tests at temperatures of 25, 200, and 250 °C. LCF tests were carried out at a total strain amplitude (
Δε
t
/2) from 0.004 to 0.012 under a constant strain rate of 0.01 s
–1
. Transmission electron microscope images showed that cyclic loading accelerated dislocation recovery as the LCF test temperature increased. The LCF life increased as a result of improvement in the ductility associated with dislocation recovery as the test temperature increased. The LCF behavior at the test temperature range followed the Coffin–Manson equation. Empirical equation was proposed to predict the LCF life of the mold steel within the test temperature range.
Graphic Abstract
Empirical equation was proposed to predict the LCF life of the mold steel considering the total strain amplitude and test temperature, and the calculated LCF life was in good agreement well with the experimental results.