Journal ArticleDOI
Evolution of phases in P91 steel in various heat treatment conditions and their effect on microstructure stability and mechanical properties
TLDR
In this paper, the evolution of phases in modified 9Cr-1Mo P91 steel and their effects on microstructural stability and mechanical properties have been studied for specimens that were subjected to different thermal heat treatment conditions.Abstract:
To achieve high thermal efficiency, modern day thermal power plants operate at higher operating temperature and pressure which necessitates use of steels with high creep rupture strength such as modified 9Cr-1Mo steels. In the present study, the evolution of phases in modified 9Cr-1Mo P91 steel and their effects on microstructural stability and mechanical properties have been studied for specimens that were subjected to different thermal heat treatment conditions. The main focus has been to study the effect of heat treatment temperature ranging from 623 K to 1033 K (350–760 °C) on P91 steel. Further, the effect of furnace cooling, water quenching, tempering at 1273 K (1000 °C) and austenitizing on the mechanical properties and microstructure has been studied. The techniques used for material characterization were scanning electron microscopy (SEM), optical microscopy (OM) and X-ray diffraction. For low tempering temperature, i.e. 623 K (350 °C), M 23 C 6 , M 3 C, M 7 C 3, and MX precipitates have been observed with high yield strength (YS), tensile strength (UTS), hardness and low toughness. In the high temperature range, 923–1033 K (650–760 °C), fine MX, M 7 C 3 , M 23 C 6 , M 2 X, and M 3 C precipitates have been observed with low YS, UTS, hardness and high toughness. The steel tempered at 1033 K (760 °C) was observed to be having best combination of YS, UTS, hardness, toughness and ductility.read more
Citations
More filters
Journal ArticleDOI
Some studies on P91 steel and their weldments
TL;DR: In this article, microstructure evolution in P91 steel and their weldments are reviewed in as-virgin and heat treatment and creep exposure condition, and the role of grain coarsening, Cr/Fe ratio, lath widening and dislocation density on creep rupture life of base metal and weldments is discussed.
Journal ArticleDOI
Study of the fracture surface morphology of impact and tensile tested cast and forged (C&F) Grade 91 steel at room temperature for different heat treatment regimes
TL;DR: In this paper, the fracture surface of cast and forged (C&F) modified 9Cr-1Mo (P91) steels, which are subjected to different heat treatment regimes, was analyzed by using the field-emission scanning electron microscope (FE-SEM).
Journal ArticleDOI
Effect of Groove Design and Post-Weld Heat Treatment on Microstructure and Mechanical Properties of P91 Steel Weld
TL;DR: In this article, the effect of postwelding heat treatment (PWHT) and weld groove designs on the overall microstructure and mechanical properties of P91 steel pipe welds produced by the gas tungsten arc welding process was studied.
Journal ArticleDOI
Effects of carbon on the microstructures and mechanical properties of FeCoCrNiMn high entropy alloys
TL;DR: In this paper, the effects of carbon on phase composition and mechanical properties of high entropy alloys were investigated, and fine M23C6 carbides with an average size of ~230 nm were observed in the HEAs doped with carbon.
Journal ArticleDOI
Microstructure and mechanical property relationship for different heat treatment and hydrogen level in multi-pass welded P91 steel joint
TL;DR: In this paper, the effect of heat treatment condition and diffusible hydrogen level on microstructure and mechanical properties of multi-pass shielded metal arc welded (SMAW) P91 steel butt joints of 18mm thickness has been studied.
References
More filters
Journal ArticleDOI
The evolution of dislocation density during heat treatment and creep of tempered martensite ferritic steels
TL;DR: In this article, the evolution of dislocation density in two tempered martensite ferritic steels (a 12% and a 9% chromium steel, X20 and P91) during heat treatment and creep is analyzed using transmission electron microscopy (TEM) and X-ray diffraction (XRD); both methods yield results which are in good agreement when rationalizing the XRD-data based on densities of free dislocations.
Journal ArticleDOI
Microstructure and long-term creep properties of 9–12% Cr steels
TL;DR: In this article, the authors have demonstrated that long-term microstructure stability in 9-12% Cr steels under technical loading conditions is equivalent to precipitate stability and that high Cr contents of 10% and above in the steels accelerate Z-phase precipitation, which may completely dissolve fine V and Nb containing MX nitrides.
Journal ArticleDOI
Alloy design of creep resistant 9Cr steel using a dispersion of nano-sized carbonitrides
TL;DR: In this paper, a dispersion of nano-size MX nitrides of vanadium and niobium along boundaries as well as in the matrix is achieved in 9Cr-3W-3Co-VNb steel with 0.05% nitrogen.
Journal ArticleDOI
Effect of normalizing temperature on microstructural stability and mechanical properties of creep strength enhanced ferritic P91 steel
TL;DR: In this article, the effect of solutionizing temperature on microstructure and mechanical properties of CSEF P91 steel has been investigated using optical metallography and scanning electron microscopy (SEM).
Journal ArticleDOI
Some aspects of plant and research experience in the use of new high strength martensitic steel P91
Ahmed Shibli,Fred Starr +1 more
TL;DR: Shibli et al. as mentioned in this paper discussed the benefits of using high strength steels in power plants and compared some of the perceived benefits with the actual plant experience and new R&D findings.