Phase stability of reduced activation ferritic steel: 8%Cr-2%W-0.2%V-0.04%Ta-Fe

Tamura, Manabu; Hayakawa, Hiroshi; Yoshitake, Akihide; Hishinuma, A.; Kondô, Tatsuo

doi:10.1016/0022-3115(88)90384-4

Cited by 117 publications

(67 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…21) These values are close to those described by other authors for lower temperatures. 22,23) On the other hand, Ta was found in M 23 C 6 carbides after ageing the alloy F82H for up to 10 000 h 24) and, marginally, in the as-tempered state of the Eurofer97 11) and the 11Cr, RA Russian 25) steels. From the point of view of precipitation effects on mechanical properties of RA steels, coarsening of precipitates such as M 23 C 6 , M 6 C or Laves phases is known to diminish the material toughness at elevated temperatures.…”

Section: C 6 M 7 C 3 or M 6 C Carbidesmentioning

confidence: 94%

Thermodynamic Modeling in Reduced Activation Steels

Danón

Servant

2005

ISIJ Int.

View full text Add to dashboard Cite

Reduced Activation (RA) martensitic steels of the 9/11CrWVTa type are promising candidates for fusion reactor applications as long as they exhibit good mechanical properties-similar to those of commercial martensitic steels of the 9/12CrMo(NbV) type-and satisfy design criteria related to the behavior under irradiation. A contribution on thermodynamic modeling in RA steels is presented. The current status of the development of a thermodynamic database in the framework of the CALPHAD approach is reported. Thermodynamic calculations concerning RA alloys are discussed which can be helpful to interpret experimental observations on phase relationships, phase compositions, transition temperatures, etc.

show abstract

Section: C 6 M 7 C 3 or M 6 C Carbidesmentioning

confidence: 94%

Thermodynamic Modeling in Reduced Activation Steels

Danón

Servant

2005

ISIJ Int.

View full text Add to dashboard Cite

show abstract

“…FETA2 is strengthened by TaN 16) and F-82H is strengthened by TaC besides martensite and M 23 C 6 . 30,31) Comparing the data of FETA2 with F-82H, it is probable that t r of FETA2 exceeds that of F-82H at a low stress level, though the number of data is limited, because the slope of the stress vs. time to rupture relation of F-82H is much larger than that of FETA2. FETA2 is aged at 650°C for 500 h before the tests, so that the new precipitation of TaN during the test can be neglected.…”

Section: Regression Analyses and Rupture Strengthmentioning

confidence: 99%

“…In the steel M 23 C 6 and TaC are formed in the sub-grains and/or on the sub-gain boundaries, lath boundaries or cell boundaries and the size of M 23 C 6 of the normalized and tempered state is ranging from about 0.05 to 0.6 mm. 30,31) TaC particles could not be distinguished clearly in the thin films from the other contrast, because of the existence of both M 23 C 6 particles and bend contour lines in addition to the small size of TaC. However, the previous work 30) reported that the average size of TaC extracted on a replica film is 27 nm in the same steel of the normalized tempered state and the size does not drastically change even after the thermal aging at 650°C for 30 000 h.…”

Section: Figures 8 Andmentioning

confidence: 99%

“…Concerning F-82H, the inter particle distance of M 23 C 6 is estimated as a value of a normalized and tempered state. The amount of precipitates of M 23 C 6 may not change, 31) but the particle size should be increasing gradually, so that the inter particle distance of M 23 C 6 may increase during creep. However, the change may be not so large, because the test duration is short.…”

Section: Comparison Of D/p With Substructure (1) Sub-grain Sizementioning

confidence: 99%

See 1 more Smart Citation

Relation between Creep Rupture Strength and Substructure of Heat Resistant Steel.

et al. 2002

Self Cite

View full text Add to dashboard Cite

Creep rupture tests were performed at around 650°C on a low carbon steel, a W-bearing low carbon steel, a low carbon steel containing 0.1 % of TaN and a 0.1%C-8%Cr-2%W-0.2%V-0.04%Ta steel (F-82H), structural material for fusion reactors. The equivalent obstacle spacing for mobile dislocations is calculated using only rupture data according to the creep theory developed by some of the authors. Thin films taken from the ruptured specimens were examined under a transmission electron microscope (TEM). The observed sub-grain size or the calculated inter-particle distance roughly coincides with the equivalent obstacle spacing. This indicates that the microscopic variable, i.e. the obstacle spacing for mobile dislocations, such as sub-grain size or inter-particle distance, can be directly calculated from only the macroscopic variable, i.e. time to rupture or creep rate.

show abstract

“…Steel of F82H [1][2][3] is planned to use for a Japanese ITER test blanket module. 4) According to the trial design the test blanket is fabricated by mainly hot isostatic pressing and tungsten inert gas welding 5) and the total mass of a unit module exceeds 2 ton.…”

Section: Introductionmentioning

confidence: 99%

Creep Behavior of Double Tempered 8%Cr-2%WVTa Martensitic Steel

Tamura

Nowell²,

Shinozuka

et al. 2006

Mater. Trans.

View full text Add to dashboard Cite

Creep testing was carried out at around 650 C for a martensitic 8Cr-2WVTa steel (F82H), which is a candidate alloy for the first wall of the fusion reactors of the Tokamak type. Rupture strength of the double tempered steel (F82HD) is lightly higher than that of simply tempered steel (F82HS). On the other hand, creep rate of F82HD is obviously smaller than that of F82HS in acceleration creep, though creep strain of F82HD in transition creep, where creep rate decreases with increasing strain, is larger than that of F82HS. Hardness of the crept F82HD decreases with increasing creep strain, which corresponded with the transmission electron microscopy (TEM) observation. On the contrary, X-ray diffraction and electron back-scattered diffraction pattern measurements show that fine sub-grains are created during transition creep. The creep curves were analyzed using an exponential type creep equation and the apparent activation energy, the activation volume and the pre-exponential factor were calculated as a function of creep strain. Then, these parameters were converted into two parameters, i.e. equivalent obstacle spacing (EOS) and mobile dislocation density parameter (MDDP). While EOS decreases with increasing creep strain, MDDP increases with increasing strain during transition creep. The decrease in EOS and the increase in either EOS or MDDP are rate-controlling factors in transition and acceleration creep, respectively. On the other hand, in case of F82HS, EOS increases and MDDP decreases during transition creep. In this case, the decrease in MDDP controls the creep rate during transition creep of F82HS. It is concluded that both EOS and MDDP are representative parameters of the change in substructure during creep.

show abstract

Phase stability of reduced activation ferritic steel: 8%Cr-2%W-0.2%V-0.04%Ta-Fe

Cited by 117 publications

References 7 publications

Thermodynamic Modeling in Reduced Activation Steels

Thermodynamic Modeling in Reduced Activation Steels

Relation between Creep Rupture Strength and Substructure of Heat Resistant Steel.

Creep Behavior of Double Tempered 8%Cr-2%WVTa Martensitic Steel

Contact Info

Product

Resources

About