Effects of prior austenite grain size on impression creep and microstructure in simulated heat affected zones of boron modified P91 steels

Ахтар, Модассир; Khajuria, Akhil

doi:10.1016/j.matchemphys.2020.122847

Cited by 32 publications

(27 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Souissi et al [54] revealed that B in the interstitial and substitutional sites had very close dissolution enthalpies; thus, it can be thermodynamically stable at both sites. Akhtar et al [55] observed different types of diffusion mechanisms and further confirmed the interstitial and substitutional nature of B in studies on the activation energy and diffusion mechanism of B in P91 steels. The low active energy was attributed to grain boundary (GB)-diffusion/impurity-vacancy diffusion, leading to occupation of B at interstitial sites.…”

Section: Boronmentioning

confidence: 60%

Effects of Alloying Elements and Microstructure on Stainless Steel Corrosion: A Review

Sun

Tang

Wang

et al. 2021

steel research int.

View full text Add to dashboard Cite

Stainless steel has attracted significant attention in industrial and engineering applications. To improve its corrosion resistance, there are two major approaches that are to optimize the elemental composition and tune the microstructure. A comprehensive review of the main findings on the corrosion of stainless steel is presented, and some controversial issues are highlighted. First, the functional roles of alloying elements are discussed, including nonmetallic (B, C, and N) and metallic (Cr, Ni, Cu, and Mo) elements. Additionally, their detrimental and positive effects, as well as the corresponding mechanisms, are highlighted. Second, the microstructure‐induced corrosion of stainless steel is discussed, including the crystallographic‐orientation‐dependent corrosion, the dual influence of grain size and grain boundary distribution, texture, and defects in the matrix. In addition, nanostructured materials are mentioned herein. Third, challenges as well as research trends in the future are proposed with perspectives for the development of novel stainless steel in research and industrial applications.

show abstract

Section: Boronmentioning

confidence: 60%

Effects of Alloying Elements and Microstructure on Stainless Steel Corrosion: A Review

Sun

Tang

Wang

et al. 2021

steel research int.

View full text Add to dashboard Cite

show abstract

“…15,16,23 Phase transformations in terms of overall microstructural evolution that occurred during simulation of singular HAZ specimens and subsequent PWHT had a strong linkage to T P and hold time at T P . 11,12,17,18,40 Therefore, improved creep functionality of B-PM and its subzones of HAZ over standard P91 counterparts could be explained by microstructural manifestations such as evolution of lattice strain. The distribution of lattice strain remained similar for CGHAZ and B-CGHAZ, respectively, and is primarily due to highest T P that led to complete transformation giving lath martensitic structure with the dissolution of precipitates as grain boundaries exhibited negligible LAM (Figures 6(c), (d), and 7(b)).…”

Section: Resultsmentioning

confidence: 99%

“…In previous studies, the creep-damage tolerance factor [ ω ] was used to cognize effects of creep-ductility, which synergistically rationalized the mutual effects of impression strain, SSCR, and creep-rupture life. 17 This parameter is also useful to scrutinize embrittlement/hardening and is represented as equation 13.…”

Section: Resultsmentioning

confidence: 99%

“…12,17 However, microstructural as well as creep mechanisms that mitigate type IV failure on additions of small concentration of boron to P91 steel are still being researched. 17–25 The gravity of this issue has been summarized in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

“…16 The effects of prior-austenite grain size on impression creep measurements and nucleation of dissolution different phases due to boron modification were already reported in detail elsewhere. 12,17 However, microstructural as well as creep mechanisms that mitigate type IV failure on additions of small concentration of boron to P91 steel are still being researched. 17–25 The gravity of this issue has been summarized in Figure 1.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A novel approach to envisage effects of boron in P91 steels through Gleeble weld-HAZ simulation and impression-creep

Khajuria

Ахтар

Bedi

2021

The Journal of Strain Analysis for Engineering Design

Self Cite

View full text Add to dashboard Cite

This paper induced a novel methodology for the characterization of creep behavior of weld heat-affected zone (HAZ) for boron-free P91 (PM) and boron modified P91B (B-PM) steels. Gleeble-3800 thermo-mechanical simulator replicated specimens, representing coarse-grain HAZ (CGHAZ), fine-grained HAZ (FGHAZ), and inter-critical HAZ (ICHAZ). Short-term impression creep tests were conducted at 625°C/270-410MPa on PM/B-PM and their simulated HAZs after being subjected to post-weld heat treatment (PWHT) of 760°C/3 h. Microstructural characterization and local strain analyses were accomplished by electron back-scattered diffraction. Simulated microstructures of P91B-FG/ICHAZ after PWHT exhibited lath martensitic structure and large prior-austenite grain size as regards P91-FG/ICHAZ, correspondingly. Average values of local microstructural strain from local average misorientation were relatively high in B-PM and P91B-ICHAZ than PM and P91-ICHAZ, respectively. Similar observations were found for P91-CG/FGHAZ with their counterparts. Stress dependent steady-state creep-rate (SSCR) followed power-law for all specimens except PM. The minimum and maximum ranges of SSCR for P91B specimens were observed to be in a narrower range than P91 specimens. The value of stress exponent for all specimens was evaluated, and corresponding mechanisms were discussed. The analyses of microstructures and corresponding impression creep behavior of P91/P91B samples suggested that modification of 100 ppm boron to P91 steel improved creep-rupture ductility that delayed type IV failure at outer HAZ of P91 steel weldments.

show abstract

The Synergistic Effects of Boron and Impression Creep Testing during Paced Controlling of Temperature for P91 Steels

Ахтар

Khajuria

2023

Adv Eng Mater

Self Cite

View full text Add to dashboard Cite

This article induces the quadruple knowledge on effects of 100 ppm (P91B) and 22 ppm (P91) boron in as‐received 9Cr steels in normalized and tempered conditions (NT) and impression crept conditions (ICC). Herein, impression creep testing is improved through paced temperature to fast evaluate creep performance. P91B performs the utmost by advancing activation energy and 30% better creep life, leading to same targeted creep life to 574 °C than P91 at 550 °C. Further, it incisively discusses variations in microstructure, precipitate size, geometrically necessary dislocations (GNDs), pseudo‐rocking curve, grain size (GS), several types of grain boundaries (GBs), effective GB energy, and elastic stiffness. Novel phenomenological mechanisms like GB hardening/softening; antithetical mechanisms; boron‐dependent mosaicity; grain refinement/fragmentation/coarsening/homogenization; interaction among various types of GBs, triggering re/degeneration of dislocations and Σ boundaries as Σ reactions; super‐continuous and geometric dynamic recrystallizations; enhanced creep immunity of like‐oriented GBs than unlike oriented GBs; primary/secondary recrystallization; specialness; boron/NT/ICC‐dependent stiffness; high stiffness is dependent on low GNDs and big GS, and vice versa are observed. The synergistic effects of [100 ppm boron in NT/ICC] and ICC in manifestation of 22/100 ppm boron are ascertained. However, dependency [proportionally and antithetically] and independency of GB character on creep‐microstructural reciprocity discourse and converse into the mathematical relationship.

show abstract

Effects of prior austenite grain size on impression creep and microstructure in simulated heat affected zones of boron modified P91 steels

Cited by 32 publications

References 31 publications

Effects of Alloying Elements and Microstructure on Stainless Steel Corrosion: A Review

Effects of Alloying Elements and Microstructure on Stainless Steel Corrosion: A Review

A novel approach to envisage effects of boron in P91 steels through Gleeble weld-HAZ simulation and impression-creep

The Synergistic Effects of Boron and Impression Creep Testing during Paced Controlling of Temperature for P91 Steels

Contact Info

Product

Resources

About