Development of New High-Strength Carbide-Free Bainitic Steels
An attempt was made to optimize the mechanical properties by tailoring the process parameters for two newly developed high-strength carbide-free bainitic steels with the nominal compositions of 0.47 pct C, 1.22 pct Si, 1.07 pct Mn, 0.7 pct Cr (S1), and 0.30 pct C, 1.76 pct Si, 1.57 pct Mn, and 0.144 pct Cr (S2) (wt pct), respectively. Heat treatment was carried out via two different routes: (1) isothermal transformation and (2) quenching followed by isothermal tempering. The results for the two different processes were compared. The bainitic steels developed by isothermal heat treatment were found to show better mechanical properties than those of the quenched and subsequently tempered ones. The effect of the fraction of the phases, influence of the transformation temperatures, the holding time, and the stability of retained austenite on the mechanical properties of these two steels was critically analyzed with the help of X-ray diffraction, optical metallography, scanning electron microscopy, and atomic force microscopy. Finally, a remarkable combination of yield strength of the level of 1557 MPa with a total elongation of 15.5 pct was obtained.
Supplementary Material (0)
About this Article
- Development of New High-Strength Carbide-Free Bainitic Steels
- Open Access
- Available under Open Access This content is freely available online to anyone, anywhere at any time.
Metallurgical and Materials Transactions A
Volume 42, Issue 13 , pp 3921-3933
- Cover Date
- Print ISSN
- Online ISSN
- Springer US
- Additional Links
- Industry Sectors
- Author Affiliations