Effect of long-term ageing on microstructure stability and lattice parameters of coexisting phases in intermetallic Ti–46Al–8Ta alloy

2011 ◽  
Vol 19 (1) ◽  
pp. 121-124 ◽  
Author(s):  
J. Lapin ◽  
T. Pelachová ◽  
V.T. Witusiewicz ◽  
E. Dobročka
Keyword(s):  
Lattice Parameters ◽  
Microstructure Stability ◽  
Coexisting Phases

Investigation on long-term creep rupture properties and microstructure stability of Fe–Ni based alloy Ni–23Cr–7W at 700°C

2013 ◽  
Vol 565 ◽  
pp. 285-291 ◽  
Author(s):  
Tsuyoshi Tokairin ◽  
Kristian Vinter Dahl ◽  
Hilmar Kjartansson Danielsen ◽  
Flemming Bjerg Grumsen ◽  
Takashi Sato ◽  
...  
Keyword(s):  
Creep Rupture ◽  
Microstructure Stability ◽  
Term Creep ◽  
Rupture Properties

scholarly journals Experimental Investigation of Isothermal Section of the B-Cr-Fe Phase Diagram at 1353 K

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Viera Homolová ◽  
Lucia Čiripová
Keyword(s):  
Isothermal Section ◽  
Ternary Phase ◽  
Fe Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Third ◽  
Coexisting Phases ◽  
Scanning Electron

The isothermal section of the B-Cr-Fe ternary system was studied experimentally at 1353 K. X-ray diffraction and scanning electron microscopy equipped with EDX analyzer were used for determination of phase equilibria and composition of the coexisting phases in the B-Cr-Fe model alloys after long-term annealing (1500–2205 h). Two iron borides FeB and Fe2B, six chromium borides Cr2B, Cr5B3, CrB, Cr3B4, CrB2, and CrB4 and also iron and chromium solid solutions (α(Fe,Cr), α(Cr,Fe), γ(Fe,Cr)) and β-rhombohedral B were observed in the alloys. High solubilities of the third element in binary borides and no ternary phase were found. Based on the experimental results, isothermal section of the B-Cr-Fe system at 1353 K was determined.

scholarly journals Effect of Long-Term High Temperature Oxidation on the Coking Behavior of Ni-Cr Superalloys

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1899 ◽  
Author(s):  
Stamatis Sarris ◽  
Manjunath Patil ◽  
Kim Verbeken ◽  
Marie-Françoise Reyniers ◽  
Kevin Van Geem
Keyword(s):  
Cross Section ◽  
Temperature Oxidation ◽  
X Ray ◽  
Microstructure Stability ◽  
Ni Content ◽  
Steam Cracking ◽  
Improved Stability ◽  
Section Analysis

The service time of an industrial cracker is strongly dependent on the long-term coking behavior and microstructure stability of the reactor coil alloy. Super alloys are known to withstand temperatures up to even 1400 K. In this work, several commercially available alloys have been first exposed to a long term oxidation at 1423 K for 500 h, so-called metallurgic aging. Subsequently, their coking behavior was evaluated in situ in a thermogravimetric setup under ethane steam cracking conditions (Tgasphase = 1173 K, Ptot = 0.1 MPa, XC2H6 = 70%, continuous addition of 41 ppmw S/HC of DMDS, dilution δ = 0.33 kgH2O/kgHC) and compared with their unaged coking behavior. The tested samples were also examined using scanning electron microscopy and energy diffractive X-ray for surface and cross-section analysis. The alloys characterized by increased Cr-Ni content or the addition of Al showed improved stability against bulk oxidation and anti-coking behavior after application of metallurgic aging due to the formation of more stable oxides on the top surface.

Thermal Stability of Ti-6Al-4V Alloy with Carbon Content

2015 ◽  
Vol 226 ◽  
pp. 23-28
Author(s):  
Agnieszka Szkliniarz
Keyword(s):  
Carbon Content ◽  
Operating Temperature ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Hardness Test ◽  
Two Phase ◽  
Microstructure Stability ◽  
The Stability ◽  
Thermal Stability Of

In the paper, the effect of long-term annealing (to 500 h) on the microstructure and hardness of two-phase titanium alloy which represent group of α+β (Ti-6Al-4V) with 0.7 wt. % carbon content was present. The stability of microstructure after long-term annealing was conducted to alloys in hardening state (after solution treatment and aging). Annealing was carried out at a temperature above the operating temperature of commercial titanium alloys without carbon content. The analysis of changes in the microstructure at research range of annealing time indicates its stability, which was confirmed by hardness test of investigated alloys. For comparison to Ti-6Al-4V-0.7C alloy, the microstructure stability research at 420oC was conducted for classical alloy contain no carbon. This alloy was previously subject solution and aging treatment under the same conditions as tested alloy.

scholarly journals Effects of Yttrium on Microstructure Stability and Tensile Properties of China Low Activation Martensitic Steel

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 446 ◽  
Author(s):  
Guoxing Qiu ◽  
Dongping Zhan ◽  
Changsheng Li ◽  
Min Qi ◽  
Yongkun Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Martensitic Steel ◽  
Electron Backscatter Diffraction ◽  
Boundary Migration ◽  
Grain Boundary Migration ◽  
Microstructural Stability ◽  
Microstructure Stability ◽  
Transmission Electron ◽  
Backscatter Diffraction

This study investigated the microstructural stability and mechanical properties exhibited by China low activation martensitic (CLAM) steels with different yttrium (Y) contents over 3000 h of aging at 550 °C. Scanning electron microscopy, electron backscatter diffraction analysis, and transmission electron microscopy were employed to investigate the microstructural evolution of the steels. Results indicated that grain boundary migration was slow and the Laves phase precipitation was delayed in Y-containing steels. Grain boundaries at different angles in 0Y and 6Y CLAM steels were significantly affected, and those in 36Y and 71Y alloys exhibited negligible changes during the long-term thermal aging. Moreover, Y contents had appreciable effects on the strength and toughness of the aged steels. The stable microstructure of Y-containing CLAM alloys is responsible for improved strength and impact toughness during aging.

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