4. (a) Why are the steel gears case hardened? How it is done? (b) For a...
3. For a steel alloy it has been determined that a carburizing heat treatment of 10 h duration will raise the carbon concentration to 0.45 wt% at a point 2.5 mm from the surface. Estimate the time necessary to achieve the same concentration at a 5.0 mm position for an identical steel and at the same carburizing temperature. [40]
Current Attempt In Progress For a steel alloy it has been determined that a carburizing heat treatment of 17 h duration at 700'C will raise the carbon concentration to 0.39 wt at a point 3.9 mm from the surface. Estimate the time necessary to achieve the same concentration at a 7.7 mm position for an identical steel and at a carburizing temperature of 1030°C. Assume that Dois 3.1 * 10 m/s and Q, is 103 kJ/mol. e Textbook and Media...
2.4 For a steel alloy it has been determined that a carburizing heat treatment of 5-h duration will raise the carbon concentration to 0.45 wt% at a point 2.5 mm from the surface. Estimate the time necessary to achieve the same concentration at a 5.0-mm position for an identical steel and at the same carburizing temperature. Dt 2 2. 2. 2.
(10 points) Problem S. For a steel alloy it has been determined that a carburizing heat treatment of 10-h ime necessary to achieve the same concentration at a 5.0-mm position for an identical steel and at the duration will raise the carbon concentration to 0.45 wt% at a point 2.5 mm from the surface. Estimate the same carburtzing temperature
6. (10) For a steel alloy at 900'C, it has been determined that a carburizing heat treatment of 8 hours will raise the carbon concentration to 0.35 W% at a point 0 mm from the surface. If the same steel is left in the furnace for 150 hours, to what depth below the surface will there be a carbon concentration of 0.35 wt%? Must show work and support any assumptions. Do = D exf toRT 10
6. (10) For a...
2 a) It is given that a carburizing heat treatment of 10-hour duration of a steel alloy will raise the carbon content to 0.45 wt% at a point 2.5 mm away from the surface. Compute the time required to get the same concentration at a 5.0-mm position from the surface at the same carburizing temperature for an identical steel alloy (Hint: The diffusion coefficient will be a constant for two identical materials at a given temperature). b) What is the...
10. A 1020 steel is carburized and a case depth of 0.25 mm is needed. The case depth is defined at the depth at which the carbon concentration is 0.6 wt%. The surface concentration during carburizing is 1.2 wt%. Determine the carburizing time needed if T = 900K. Repeat for 1050K.
10. A 1020 steel is carburized and a case depth of 0.25 mm is needed. The case depth is defined at the depth at which the carbon concentration is...
In the carburizing process the steel piece was exposed, at an elevated temperature (900 °C), to an atmosphere rich in a hydrocarbon gas, such as methane CH Surface concentration of carbon is to be maintained at 1.18 wt%. Determine the time (in hours) necessary to achieve a carbon content of 0 68 wt% at a position 0.8 mm below the surface. Initial carbon concentration is 0 18 wt% Take the diffusion coefficient for carbon in iron at 900°C = 1.0...
4. For a steel alloy it has been determined that a carburizing hea t treatment of 10-h duration Wll concentration to 0.45 wt% at a point 5.5-mm from the surface. Estimate the po concentration in 6 hours (identical steel and at the Tip: The short erf(Z) table found on last page sition that will achieve the same same carburizing temperature). 5. Consider a single crystal of silver oriented such that a tensile (15) stress is applied along a [001] direction....
UTVER VIS Concentration of Nitrogen (wt%): = 0.21 Position in mm= 7.2 Diffusion Coefficient for Nitrogen in Iron at 700°C -8.90E-10 Nitrogen in Iron Heat Treatment Time (hours): = 8 Carburizing Time (hrs): = 7 Steel Alloy Case Depth (mm): 4.8 Steel Alloy New Case Depth (mm) - 9.9 Activation Energy kJ/mol: = 103 Temperature for Problem 3 (Celsius) -809 . Data for Problem 4 Temperature in C: -595 Diffusivity (m2/s) = 5.62E-14 Temperature in C: -702 Diffusivity (m /s)...