Chemistry

You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 235.0 ppm and is initially uniform through the thickness of the steel. The atmosphere of the carburizing furnace maintains a carbon concentration of 7345.0 ppm at the surface of the steel. Calculate the time required to carburize steel so that the concentration of carbon at a depth of 62.5 x 10-2 cm is one half the value of the carbon concentration at the surface. The diffusion coefficient of carbon in steel is 3.091 x 10-7 cm2/s at the carburizing temperature. Express your answer in hours.

  1. 👍 0
  2. 👎 0
  3. 👁 211
  1. Step 1:

    ξ= (0.5 * carbon concentration at the surface of the steel - carbon concentration at the surface of the steel)/ (carbon concentration in the steel before carburization - carbon concentration at the surface of the steel)

    (0.5* 7345.0 - 7345.0)/ ( 235.0 - 7345.0)= erf(ξ)

    Step 2:
    erf(ξ < 0.6), use the approximation erf ξ = ξ

    Step 3:

    t= d^2/4*D*ξ^2

    d=62.5 x 10-2 cm
    D=3.091 x 10-7 cm2/s

    Step 4:
    t in sec -> hours
    Conversion seconds to hours is total/(60x60)

    1. 👍 0
    2. 👎 0
    posted by Odesa

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 206.5 ppm and is initially uniform

    asked by y on December 15, 2012
  2. science

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 152.0 ppm and is initially uniform

    asked by fatine on December 16, 2012
  3. Chemistry

    to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 200.5 ppm and is initially uniform through the

    asked by Ankur on December 15, 2012
  4. chemistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 141.0 ppm and is initially uniform

    asked by troubled student on December 14, 2012
  5. chemistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 390.5 ppm and is initially uniform

    asked by mike on December 15, 2012
  6. chemistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 165.0 ppm and is initially uniform

    asked by student on December 14, 2012
  7. chimistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 100.0 ppm and is initially uniform

    asked by School girl on December 14, 2012
  8. Chemistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 359.5 ppm and is initially uniform

    asked by T on December 15, 2012
  9. Chemistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 193.5 ppm and is initially uniform

    asked by Odesa on December 14, 2012
  10. Chemistry

    You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 200.5 ppm and is initially uniform

    asked by Ankur on December 15, 2012

More Similar Questions