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Fig. 5. Thermal conductivity versus temperature. Open circles: Eurofer 97 using Eqs. (1), (4) and (6). Solid circles: Eurofer 97 from the experimental data points of diffusivity and specific heat (Figs. 3 and 4) and using Eq. (1). Open triangles: F82H according to Ref. [14]. The continuous and dotted lines are the least squares fitted equations (10) and (11). Insert: open circles experimental thermal resistivity values of Eurofer 97, continuous line the least squares fitted equation (9). coefficient for Eurofer 97 and F82H 1s very similar for tem- peratures up to 800 K and the mean difference of their values at a given temperature is about 10%. The empirical equa- tions which describe the temperature dependence of the ther- mal diffusivity of these two alloys is given by the equations:

Figure 5 Thermal conductivity versus temperature. Open circles: Eurofer 97 using Eqs. (1), (4) and (6). Solid circles: Eurofer 97 from the experimental data points of diffusivity and specific heat (Figs. 3 and 4) and using Eq. (1). Open triangles: F82H according to Ref. [14]. The continuous and dotted lines are the least squares fitted equations (10) and (11). Insert: open circles experimental thermal resistivity values of Eurofer 97, continuous line the least squares fitted equation (9). coefficient for Eurofer 97 and F82H 1s very similar for tem- peratures up to 800 K and the mean difference of their values at a given temperature is about 10%. The empirical equa- tions which describe the temperature dependence of the ther- mal diffusivity of these two alloys is given by the equations:

Related Figures (9)

Fig. 1. Neutron diffraction data from Eurofer 97. The continuous line is a fit to the data after Rietveld refinement. In Fig. 1 the neutron diffraction data and the corre- sponding curve obtained by using the Fullprof Rietveld [12] program are presented. The Eurofer 97 as the Fe—Cr
Fig. 1. Neutron diffraction data from Eurofer 97. The continuous line is a fit to the data after Rietveld refinement. In Fig. 1 the neutron diffraction data and the corre- sponding curve obtained by using the Fullprof Rietveld [12] program are presented. The Eurofer 97 as the Fe—Cr
Fig. 4. Specific heat of Eurofer 97 (solid circles) as a function of temperature. The data for F82H (open triangles) are according to Ref. [14]. The continuous and dotted lines are the least squares fitted equations (6) and (7). Insert: Magnetic specific heat for Eurofer 97 (for details see text). Fig. 3. Thermal diffusivity of Eurofer 97 (solid circles) as a function of temperature. The data for F82H (open triangles) are according to Ref. [14]. The continuous and dotted lines are the least squares fitted equations (4) and (5).
Fig. 4. Specific heat of Eurofer 97 (solid circles) as a function of temperature. The data for F82H (open triangles) are according to Ref. [14]. The continuous and dotted lines are the least squares fitted equations (6) and (7). Insert: Magnetic specific heat for Eurofer 97 (for details see text). Fig. 3. Thermal diffusivity of Eurofer 97 (solid circles) as a function of temperature. The data for F82H (open triangles) are according to Ref. [14]. The continuous and dotted lines are the least squares fitted equations (4) and (5).
The thermal diffusivity of Eurofer 97 is much lower than the corresponding values of Fe and Cr, which at room temperature are 0.227 and 0.26cm7/s, respectively [15]. The temperature dependence of the thermal diffusivity
The thermal diffusivity of Eurofer 97 is much lower than the corresponding values of Fe and Cr, which at room temperature are 0.227 and 0.26cm7/s, respectively [15]. The temperature dependence of the thermal diffusivity
Fig. 2. (a) Bright field overview of the grain/subgrain structure. (b) Typical coarse precipitation at subgrain boundaries of Eurofer 97.
Fig. 2. (a) Bright field overview of the grain/subgrain structure. (b) Typical coarse precipitation at subgrain boundaries of Eurofer 97.
Fig. 7. Hysteresis loop of Eurofer 97 at room temperature. Insert: the centre of the hysteresis loop. From a plot of the magnetization versus 1/H* the satura- tion magnetization is determined from the intercept of the least squares fitted line. The temperature dependence of the coercive field, the remanence and the saturation magnetization, are presented in Figs. 8-10. For compari- son the corresponding data for the steel F82H [14] are also presented. We observe that the coercive field for F82H for all the temperatures reported is 1.5 times larger than that for Eurofer 97. An average 5% difference is observed in M, between Eurofer 97 and F82H, which is almost con- stant over the temperature range reported for both alloys. The values of M, for F82H are not shown in Fig. 9 because in Ref. [14] it is not stated whether the correction for the demagnetizing field has been applied. It has to be noted that the demagnetizing field correction has a significant effect on the remanence magnetization values but not on the coercive field values.
Fig. 7. Hysteresis loop of Eurofer 97 at room temperature. Insert: the centre of the hysteresis loop. From a plot of the magnetization versus 1/H* the satura- tion magnetization is determined from the intercept of the least squares fitted line. The temperature dependence of the coercive field, the remanence and the saturation magnetization, are presented in Figs. 8-10. For compari- son the corresponding data for the steel F82H [14] are also presented. We observe that the coercive field for F82H for all the temperatures reported is 1.5 times larger than that for Eurofer 97. An average 5% difference is observed in M, between Eurofer 97 and F82H, which is almost con- stant over the temperature range reported for both alloys. The values of M, for F82H are not shown in Fig. 9 because in Ref. [14] it is not stated whether the correction for the demagnetizing field has been applied. It has to be noted that the demagnetizing field correction has a significant effect on the remanence magnetization values but not on the coercive field values.
Fig. 6. The specific electrical resistivity of Eurofer 97 versus temperature. The continuous line is the least squares fitted equation (12). The open squares correspond to the electrical resistivity values from grade 91 steel [15]. Insert: the resistivity corresponding to the magnetic scattering of conduction electrons (see text for details). where the factor G depends on the spin of the magnetic atom [18] and the variation of (S) with temperature may be derived from the magnetization versus temperature curve. Using Eq. (18) for the magnetization and the value of G from Ref. [17] corresponding to experimentally deter- mined mean magnetic moment of 1.851g/atom (see section 3.2.3) the resistivity arising from the magnetic scattering of the conduction electrons has been calculated and it is pre- sented in the insert of Fig. 6. If from the total specific resis- tivity the magnetic contribution is subtracted we find that
Fig. 6. The specific electrical resistivity of Eurofer 97 versus temperature. The continuous line is the least squares fitted equation (12). The open squares correspond to the electrical resistivity values from grade 91 steel [15]. Insert: the resistivity corresponding to the magnetic scattering of conduction electrons (see text for details). where the factor G depends on the spin of the magnetic atom [18] and the variation of (S) with temperature may be derived from the magnetization versus temperature curve. Using Eq. (18) for the magnetization and the value of G from Ref. [17] corresponding to experimentally deter- mined mean magnetic moment of 1.851g/atom (see section 3.2.3) the resistivity arising from the magnetic scattering of the conduction electrons has been calculated and it is pre- sented in the insert of Fig. 6. If from the total specific resis- tivity the magnetic contribution is subtracted we find that
Fig. 8. The temperature dependence of the coercive field for Eurofer 97 (solid circles). The open triangles correspond to F82H data according to Ref. [14]. The continuous line is the least squares fitted equation (16). Insert: Solid circles UTS data for Eurofer 97 according to reference [9], continuous line equation (19).
Fig. 8. The temperature dependence of the coercive field for Eurofer 97 (solid circles). The open triangles correspond to F82H data according to Ref. [14]. The continuous line is the least squares fitted equation (16). Insert: Solid circles UTS data for Eurofer 97 according to reference [9], continuous line equation (19).
Fig. 9. The temperature dependence of the remanence magnetization for Eurofer 97 (solid circles). The continuous line is the least squares fitted equation (17).
Fig. 9. The temperature dependence of the remanence magnetization for Eurofer 97 (solid circles). The continuous line is the least squares fitted equation (17).
Fig. 10. The temperature dependence of the saturation magnetization for Eurofer 97 (solid circles). The open triangles correspond to F82H data according to Ref. [14]. The continuous line is the least squares fitted equation (18).
Fig. 10. The temperature dependence of the saturation magnetization for Eurofer 97 (solid circles). The open triangles correspond to F82H data according to Ref. [14]. The continuous line is the least squares fitted equation (18).
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