An FCC iron-carbon alloy initially containing 0.20 wt% C is carburized at an elevated temperature and in an atmosphere wherein the surface carbon concentration is maintained at 1.0 wt%. If after 51 h the concentration of carbon is 0.35 wt% at a position 3.5 mm below the surface, determine the temperature at which the treatment was carried out. You will need to use data in the two tables below to solve this problem. Diffusing Species Fe Table 5.1 Tabulation of Error Function Values erf(z) 0 0.0282 0.0564 0.1125 Fe Z 0 0.025 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50 Table 5.2 A Tabulation of Diffusion Data Host Metal a-Fe (BCC) y-Fe (FCC) a-Fe 0.1680 0.2227 0.2763 0.3286 0.3794 y-Fe 0.4284 0.4755 0.5205 Z 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.0 1.1 1.2 Do(m²/s) 2.8 x 10-4 5.0 x 10-5 6.2 x 10-7 2.3 x 10-5 erf(z) 0.5633 0.6039 0.6420 0.6778 0.7112 0.7421 0.7707 0.7970 0.8209 0.8427 0.8802 0.9103 80 284 Z 1.3 1.4 1.5 1.6 1.7 1.8 1.9 Activation Energy Qa kJ/mol eVlatom 251 2.60 148 2.0 2.2 2.4 2.6 2.8 2.94 0.83 1.53 erf(z) 0.9340 0.9523 0.9661 0.9763 0.9838 0.9891 0.9928 0.9953 0.9981 0.9993 0.9998 0.9999 Calculated Value T(°C) 500 900 900 1100 500 900 900 1100 D(m²/s) 3.0 x 10-21 1.8 x 10-15 1.1 x 10-17 7.8 x 10-16 2.4 x 10-12 1.7 x 10-10 5.9 x 10-12 5.3 × 10-11

Please kindly help. I will give a like. Thank you! a. Describe the S-curve model of diffusion on how does ‘rate of adoption’ change over time? At which-point is the rate of diffusion the fastest? b. S-curve model of diffusion: (true/false) and reasoning - k = 0, the rate of diffusion is instantaneous? - fixed k ≥ 0, the carrying capacity is determined only by the ratio of a and b? - fixed k ≥ 0, the rate of diffusion is determined only by the ratio of a and b? c. The diffusion of hybrid corn in the 1940s, who or which region seems to have adopted the hybrids more quickly and why?

Which best explains why the trend in noble gas boiling points increases down the group (larger in size)?   A. Increasing dipole-dipole interactions   B. Increasing dispersion interactions   C. Increasing ion-ion interactions   D. Increasing hydrogen bonding interactions

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.Nitrogen from a gaseous phase is to be diffused into pure iron at 669 °C. If the surface concentration is maintained at 1.0 wt% N, what will be the concentration (wt%) 0.9 mm from the surface after 6 hours? Given: Qd = 58 kJ/mol and Do = 6.2 x 10-7 m2/s. %3D

Problem 4 The preexponential and activation energy for the diffusion of iron in cobalt are 1.1 x 105 m²/s and 253,300 J/mol, respectively. At what temperature will the diffusion coefficient have a value of 2.1 × 10-¹4 m²/s?

You want to carburize a steel drill bit in the presence of methane. The drill bit initially has a uniform carbon concentration of 0.25 wt% and is to be treated at 950 oC (1750 oF). If the concentration of carbon at the surface is suddenly brought to and maintained at 1.20 wt%, how long will it take to achieve a carbon content of 0.80 wt% at a position 0.5mm below the surface? (The diffusion coefficient for carbon in iron at this temperature is 1.6 x 10-11 m2/s.)

Compare the diffusion coefficients (in cm²/s) of nitrogen in BCC and FCC iron at the allotropic transformation temperature of 912°C. Decc -153606 X Your response differs from the correct answer by more than 10%. Double check your calculations, cm²/s -1976-7 Dicc x Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. cm2/s

Calculate the value of the diffusion coefficient D (in m2/s) at 750°C for the diffusion of some species in a metal; assume that the values of D0 and Qd are 5.6 × 10-5 m2/s and 177 kJ/mol, respectively.

[Decarburization] An FCC iron-carbon alloy initially containing carbon with the concentration, C0, is exposed to anoxygen-rich and virtually carbon-free atmosphere. Under the given conditions, the carbon diffuses from the alloy andreacts at the surface with the oxygen in the atmosphere, meaning that the carbon concentration at the surface position is maintained essentially at 0 wt% C. The subproblems are independent.(1) Determine the diffusion coefficient at the temperature T given below.  Use T = 1250 °C(2) When the value of D is given below, what position will the carbon concentration be Cx after a treatment for thetime, t? Use D = 1.93 × 10−10m2 /s; C0 = 0.35 wt%; Cx = 0.11 wt%; t = 12 hr