For a steel alloy it has been determined that a carburizing heat treatment of 14 h duration at 809°c will raise the carbon concentration to 0.54 wt% at a point 3.6 mm from the surface. estimate the time necessary to achieve the same concentration at a 6.0 mm position for an identical steel and at a carburizing temperature of 1100°c. assume that d0 is 2.5 × 10-5 m2/s and qd is 120 kj/mol.

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k