Effect of Nb Content on the Hot Deformation Behavior of S460ML Steel

• Published in: Acta metallurgica sinica : English letters Vol. 32; no. 4; pp. 526 - 534
• Main Authors: Zhang, Yu-Cheng, Meng, Zhen-Sheng, Meng, Yang, Ju, Xin-Hua, Jiang, Zhong-Hang, Ma, Ze-Jun
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society for Metals 01.04.2019; Springer Nature B.V
• Subjects: Activation energy; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Deformation; Deformation effects; Dynamic recrystallization; Grain growth; Hardening rate; High strength low alloy steels; Materials Science; Metallic Materials; Morphology; Nanotechnology; Niobium; Organometallic Chemistry; Regression analysis; Solid solutions; Spectroscopy/Spectrometry; Steel products; Strain rate; Temperature; Thermal simulators; Tribology; Hot deformation; Nb content; Deformation temperature; Dynamic recrystallization; Critical strain; Strain rate
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-018-0783-8

The hot deformation behavior of S460ML steel with different Nb contents was investigated by single-pass compression experiment on the Gleeble-1500 thermo-machine simulator at deformation temperatures ranging from 900 to 1200 °C and strain rates from 0.1 to 5.0 s −1 . The critical strain of dynamic recrystallization (DRC) under different conditions was determined by using working hardening rate-strain curves. The relationship between critical strain and peak strain of DRC was discussed. By means of regression analysis method, the hot deformation activation energy of steels and the mathematical model for predicting DRC critical strain were calculated and established, respectively. The results showed that DRC occurred during hot deformation. As the deformation temperature increased and strain rate decreased, the critical strain of DRC decreased. The critical strain ( ε c ) showed linear relationship with peak strain ( ε p ). As Nb content increased, the needed deformation temperature for occurring DRC increased, while the needed strain rate for it decreased. The activation energy for hot deformation of S460ML steel increased with increasing Nb content.