Microstructure Evolution in a Low Carbon Nb–Ti Microalloyed Steel
Reads0
Chats0
TLDR
In this paper, the micro mechanical properties, stability and 3D morphology of intragranular ferrite was studied in a low carbon microalloyed steel utilizing nano indentation, three-dimensional reconstruction techniques along with LEO1 450 scanning electronic microscopy.Abstract:
The micro mechanical properties, stability and three-dimensional (3D) morphology of intragranular ferrite was studied in a low carbon microalloyed steel utilizing nano indentation, three-dimensional reconstruction techniques along with LEO1 450 scanning electronic microscopy. The mixed microstructures of intragranular ferrite, granular bainite and lath or plate-like bainite was obtained in a Nb–Ti microalloyed steel, which was water cooled immediately after relaxation for a fixed time as hot deformation ended. The elastic modulus and hardness increased in the sequence of intragranular ferrite, granular bainite and lath or plate-like bainite by approximately 15 GPa and 0.6 GPa, respectively. On the contrary, the tempering treatment of the specimens showed that the stability of the mixed microstructures decreased in the sequence of intragranular ferrite, granular bainite and lath or plate-like bainite. The results of stability, elastic modulus and hardness indicated that intragranular ferrite was formed prior to bainite transformation. The intragranular ferrite thus effectively sectioned the prior austenite into many small zones and thus the bainite transformed at lower temperatures was restricted in the small zones. It is likely that the formation of lath or plate-like intragranular ferrite prior to bainite transformation played an important role in the refinement of mixed microstructures.read more
Citations
More filters
Journal ArticleDOI
New insights into intragranular ferrite in a low-carbon low-alloy steel
TL;DR: In this article, single and multiple nucleation events on non-metallic inclusions have been observed, leading to the intragranular formation of ferrite as a function of transformation temperature.
Journal ArticleDOI
Evolution of microstructure and precipitation state during thermomechanical processing of a X80 microalloyed steel
TL;DR: A series of anisothermal hot torsion tests were carried out to simulate hot rolling on a high-strength low-carbon CMnNbMoTi microalloyed steel corresponding to an industrial X80 grade for pipeline construction.
Journal ArticleDOI
A nanoindentation study on the micromechanical characteristics of API X100 pipeline steel
TL;DR: In this paper, the hardness characteristics of constituent micro-phases (ferrite and bainite) in a dual-phase API X100 pipeline steel were analyzed by nanoindentation experiments.
Journal ArticleDOI
Austenite grain growth and microstructure control in simulated heat affected zones of microalloyed HSLA steel
TL;DR: In this paper, the role of microalloying niobium, titanium and vanadium for controlling austenite grain growth, microstructure evolution and hardness were investigated at different simulated heat affected zones (HAZ) for high strength low alloy (HSLA) S690QL steel.
Journal ArticleDOI
Hydrogen permeation behavior in relation to microstructural evolution of low carbon bainitic steel weldments
TL;DR: In this article, the microstructures of high strength bainitic steel weldments were characterized, and their hydrogen permeability was investigated by the electrochemical permeation technique, which showed that the effective diffusion coefficient in the welded joint increases with heat input, while the hydrogen concentration at the sub-surface decreases with increasing heat input.
References
More filters
Journal ArticleDOI
Nucleation of intragranular ferrite at Ti2O3 particle in low carbon steel
TL;DR: In this paper, a local Mn-depleted zone (MDZ) has been observed to develop in the vicinity of the steel-Ti2O3 interface, which is believed to be a dominant driving force for the heterogeneous nucleation of intragranular ferrite.
Journal ArticleDOI
Ferrite nucleation potency of non-metallic inclusions in medium carbon steels
TL;DR: In this paper, the potency of various inclusions and precipitates such as SiO 2, MnO·SiO 2, MnS, Al 2 O3, Ti 2 O 3 and VN for the nucleation of intragranular ferrite has been examined.
Journal ArticleDOI
Solid-state nucleation of acicular ferrite on minerals added to molten steel
TL;DR: A technique has been developed for making samples of steel with controlled additions of powdered mineral phases as discussed by the authors, which has been studied from the point of view of the acicular ferrite microstructure, which forms when ferrite plates nucleate heterogeneously on nonmetallic inclusions.
Journal ArticleDOI
Effect of Boron on Intra-granular Ferrite Formation in Ti-Oxide Bearing Steels
TL;DR: In this paper, the effect of B on microstructure and toughness at the heat affected zone after welding thermal cycle simulations has been investigated in steels containing titanium oxide particles, which contribute to preferential nucleation of MnS and TiN precipitates on Ti2O3.
Journal ArticleDOI
Role of non-metallic inclusions in formation of acicular ferrite in low alloy weld metals
Z. Zhang,R. A. Farrar +1 more
TL;DR: In this paper, the role of non-metallic inclusions in the nucleation of acicular ferrite in low alloy C-Mn-Ni weld metals was carried out using rapid in situ quenching, transmission electron microscopy, energy dispersive X-ray spectroscopy analysis, and dilatometric techniques.