Investigation of the Crystallographic Evolution Sequence of Nano-Precipitation via HRTEM in Cu-Bearing Ultra-Low Carbon Steel.
Nanomaterials (Basel)
; 14(16)2024 Aug 10.
Article
in En
| MEDLINE
| ID: mdl-39195372
ABSTRACT
The precipitation behavior of Cu-bearing ultra-low carbon steel after step quenching and tempering at 923 K for 0.5-2.5 h was investigated. The size, quantity, and characteristic distribution of nano-precipitates were analyzed using transmission electron microscopy, and the microstructure of B2 (an ordered structure belonging to the body-centered cubic structure), 9R (a special triclinic lattice that has characteristics of rhombohedral structure), 3R (a special triclinic lattice like 9R), and FCT (face-centered tetragonal lattices) were accurately determined. The relationship between nano-precipitates and mechanical properties under different heat treatment processes was obtained, revealing that nano-precipitates effectively enhanced the yield strength of Cu-bearing ultra-low carbon steel. There were two forms of crystal structure evolution sequence of precipitation B2âmulti twin 9Râdetwined 9RâFCTâFCC and B2âmulti-twin 9Râdetwinned 9Râ3RâFCTâFCC. The morphology of the precipitated particles during the growth process changed from spherical to ellipsoidal and finally to rod-shaped. It was proven that a stable 3R structure existed due to the coexistence of 9R, 3R, and FCT structures in the same precipitate particle.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Nanomaterials (Basel)
Year:
2024
Document type:
Article
Affiliation country:
China
Country of publication:
Switzerland