Issue |
ESOMAT 2009
2009
|
|
---|---|---|
Article Number | 04010 | |
Number of page(s) | 6 | |
Section | Principles, Simulations, Materials: Advanced Materials | |
DOI | https://doi.org/10.1051/esomat/200904010 | |
Published online | 01 September 2009 |
DOI: 10.1051/esomat/200904010
Peculiarities of structure and thermomechanical strengthening of martensitic structural steels microalloyed by nitrogen
V.G. Prokoshkina, L.M. Kaputkina and M.G. MedvedevMoscow Institute of Steel and Alloys, Leninsky Prospect 4, 119049 Moscow, Russia
Published online: 1 September 2009
Abstract
The effect of thermomechanical treatments on structure and properties of structural
C(0.35-0.50)CrNiMoV steels microalloyed by nitrogen were studied using optical microscopy,
X-ray diffraction analysis and mechanical testing. The hardness of martensite change as a
function of austenitization temperature is presented for the steels with the same main
composition but various summary C and N contents. Microalloying of structural steels
by nitrogen results in complication of phase transformations and raising austenitization
temperature for quenching and HTMT. A small quantity of undissolved carbonitrides promotes
fine-grained structure preservation and heredity of the initial ascast structure. The heat
and thermomechanical treatment regimes were determined which allowed the use of
nitrogenmicroalloyed structural steels as high-strength ones. A complete dissolution of
special carbonitrides during HTMT and following low-temperature tempering provide high strength
level (by 300-500 MPa higher than for nitrogen-free analogs) combined with sufficient
ductility and fracture toughness.
© Owned by the authors, published by EDP Sciences 2009