Thermodynamics of the fcc Fe-Mn-C and Fe-Si-C alloys

Wada, Tsuguyasu; Wada, Harue; Elliott, John F.; Chipman, John

doi:10.1007/bf02643059

Cited by 85 publications

(28 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(16) provides a better representation of the diffusivity data. Equation (16) shows smaller EF values for all ternary Fe-M-C alloys, which is not surprising. The addition of Ni increases the diffusivity of carbon as shown in Fig.…”

Section: Equation For Fe-m-c Alloysmentioning

confidence: 71%

“…With a large positive k2 value for Cr the overall effect of Cr is to decrease the C diffusivity and this decrease is appropriately obtained by Eq. (16). 3) ), and shows that for each alloy addition, Eq.…”

Section: Equation For Fe-m-c Alloysmentioning

confidence: 95%

“…The diffusivity coefficient and the activation energy are constant for the equations from Table 1 However, as illustrated in multiple studies, alloy additions do alter carbon diffusion in austenite. 3,4,6,[15][16][17][18][19] Blanter (as cited in Krishtal 3) ) evaluated the effects of systematic modifications to ternary Fe-M-C alloys. Table 2.…”

Section: Equation For Fe-m-c Alloysmentioning

confidence: 99%

“…12. [15][16][17] and Zhukov and Krishtal 18) investigated the effects of alloying elements on the activity of carbon and the coefficient of carbon diffusivity for ternary Fe-M-C alloys by using thermodynamic calculations correlated with experimental data. Goldstein and Moren 19) studied the influence of cross-diffusion coefficients on carbon diffusion by the additional alloying elements in a simulated carburizing process.…”

Section: Equation For Fe-m-c Alloysmentioning

confidence: 99%

“…(16). Table 4 summarizes the resulting k-values for the eight different substitutional alloys considered by Blanter (as cited in Krishtal 3) ).…”

Section: Equation For Fe-m-c Alloysmentioning

confidence: 99%

See 4 more Smart Citations

An Empirical Model for Carbon Diffusion in Austenite Incorporating Alloying Element Effects

2011

View full text Add to dashboard Cite

The diffusion of carbon in austenite is important to the design and implementation of many steel heattreating processes. The present study proposes a simple and computationally efficient equation for the diffusion of carbon in austenite for iron-carbon alloys, as well as for steels alloyed with a variety of elements. The proposed empirical model provides a pragmatic engineering approach to this important diffusion process. The model is shown to better match the carbon diffusion profiles of several carburized steel alloys, as compared to other equations that have been reported in the literature. These other equations were primarily obtained from experiments on iron-carbon alloys, and it is not surprising that they are less accurate when compared to the proposed equation that takes the full range of alloy compositions into account.KEY WORDS: carbon diffusion; alloy effects on diffusion in austenite; empirical model; experimental data; steels.

show abstract

Section: Equation For Fe-m-c Alloysmentioning

confidence: 71%

Section: Equation For Fe-m-c Alloysmentioning

confidence: 95%

Section: Equation For Fe-m-c Alloysmentioning

confidence: 99%

Section: Equation For Fe-m-c Alloysmentioning

confidence: 99%

“…(16). Table 4 summarizes the resulting k-values for the eight different substitutional alloys considered by Blanter (as cited in Krishtal 3) ).…”

Section: Equation For Fe-m-c Alloysmentioning

confidence: 99%

See 3 more Smart Citations

An Empirical Model for Carbon Diffusion in Austenite Incorporating Alloying Element Effects

2011

View full text Add to dashboard Cite

show abstract

Diffusivity of carbon in austenitic Fe‐Si‐C alloys

Roy

Grabke

Wepner

1980

Steel Research Intl

View full text Add to dashboard Cite

show abstract

Kinetics of the carburization of iron alloys in methane‐hydrogen mixtures and of the decarburization in hydrogen

et al. 1985

View full text Add to dashboard Cite

The surface reaction kinetics have been investigated for the reaction CH4 (gas) = C (dissolved) + 2H2 (gas) on Fe and Fe‐M foils (M = Mn, Cr, Co, Ni, Sn) at temperatures between 800 and 1000°C. The resistance relaxation method was applied in a flow apparatus. The following rate equation was observed for the rate of carbon uptake where is the carbon concentration and k and k′ are the rate constants for carburization and decarburization respectively. For Fe, Fe‐10 Ni and Fe‐10 Co the value of v = 3, for the alloys with > 20% Ni as well as for all Fe‐Mn and Fe‐Cr alloys the value v = 4 results from the measurements, which indicates differences in the rate determining step. With increasing Cr, Mn, Ni, Co content the rate constants k and k′ increase. The decrease of the equilibrium carbon concentration with increasing Ni content in Fe‐Ni alloys is correlated to a fast increase of k′ and a slow increase of k with increasing Ni content. Beyond the minimum of at about 70 wt.% Ni both rate constants show a strong increase. By holding Ni at high carbon activities (aC > 0.7 at 1000°C) segregation of carbon induces a surface reconstruction which is characterized by formation of (111) planes and which reduces the reaction rates. The increase of the equilibrium carbon concentration in the systems Fe–Mn and Fe–Cr with increasing content of alloying element is correlated to a slow increase of k′ and a fast increase of k with increasing Mn or Cr content. Sn segregates to the surface and retards the reaction rate by blocking the reaction sites for the surface reaction, similar to the effects of P and S.

show abstract

Thermodynamics of the fcc Fe-Mn-C and Fe-Si-C alloys

Cited by 85 publications

References 4 publications

An Empirical Model for Carbon Diffusion in Austenite Incorporating Alloying Element Effects

An Empirical Model for Carbon Diffusion in Austenite Incorporating Alloying Element Effects

Diffusivity of carbon in austenitic Fe‐Si‐C alloys

Kinetics of the carburization of iron alloys in methane‐hydrogen mixtures and of the decarburization in hydrogen

Contact Info

Product

Resources

About