You wish to carburize 0.2 wt% C steel ball bearings. The balls have a diameter of 2.5 mm. You anneal them at 930°C in an atmosphere which fixes the surface carbon concentration at 1 wt% C. (a) How long will it take to raise the average C concentration to 0.6 wt%? (b) What is the concentration at the centre of each ball at this time?

You wish to carburize 0.2 wt% C steel ball bearings. The balls have a diameter of 2.5 mm. You anneal them at 930°C in an atmosphere which fixes the surface carbon concentration at 1 wt% C. (a) How long will it take to raise the average C concentration to 0.6 wt%? (b) What is the concentration at the centre of each ball at this time?

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

Find the diffusitivity of air in methane and the molecular diffusion of methane, if the tank filled with a mixture of methane and air at 102 kPa and 25 ⁰C is connected to another large tank filled with a different composition of methane and air also at 102 kPa and 25 ⁰C. The connection between the tanks is a tube with an inner diameter of 50 mm and length of 150 mm. The concentration of methane in one tank is 90% by mole and in the other, 5% by mole.
[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
The diffusion coefficient of Ni in Cu at 1025 C is 10-9 cm2 s-1. How long does it take for the mean square root of the distance to be 1 cm?
4
If the initial composition of the carbon steel is c0=0.3 wt%, calculate the carbon concentration (in wt%) at a distance 0.2mm from the surface of the component after 1 hour of decarburization.
What mass of NaCl must be dissolved in 65.0 g of water to lower the freezing point of water by 7.5°C? The freezing point depression constant (Kf) for water is 1.86°C/m. Assume van’t Hoff factor for NaCl is 1.87. (Molar mass of NaCl = 58.5 g)
The activation energy for the diffusion of C in Cr is 111,000 j/mol. Calculate the diffusioncoefficient at 827°C, grven that D at 1127°C is 6.25 * 10^-11 m^2/s.
Solve by hand please solve correctly please
d. An Aluminum-Copper alloy initially containing (0.4 wt% Cu) is placed and held in an atmosphere that gives a constant surface Aluminum concentration of (1.0 wt% ). If after (43 h) the concentration of copper is (0.55 wt%) at a position (4.0 mm) below the surface. What is the diffusion coefficient of copper in aluminum for the treatment conditions. z erf(z) 0.6778 0.70 0.75 0.7112 0.80 0.7421 0.85 0.7707 0.90 0.7970
Thermo-fluid Mechanics I want a quick solution
The diffusion coefficients for species A in metal B are given at two temperatures: D (m²/s) 7.81 x 10-17 7.70x 10-16 i (b) Determine the value of Do. (a) Determine the value of the activation energy Qd (in J/mol). i T (°C) 1030 i 1260 J/mol m²/s (Use scientific notation.) (c) What is the magnitude of D at 1180°C? m²/s (Use scientific notation.)
The diffusion coefficients for carbon in nickel are given at two temperatures: T(°C) D (m²/s) (a) Determine the value of Do. i (b) Determine the value of Qd. i i kJ/mol (c) What is the magnitude of D? at 810°C. 600 700 ! m²/s (Use scientific notation.) 5.5 x 10-14 3.9 × 10-13 m²/s (Use scientific notation.)