The yield stresses of several samples of a steel containing 0.12% carbon with different grain sizes were measured. The data are shown here.
Grain-Size Inverse

(b) Which sample has the grain size of 27.7 μm?
(c) Fit these data to a straight line and calculate the constants σ0 and K for the Hall-Petch equation.
(d) What is the grain size of the sample that has the highest yield strength?
(e) A sample of this steel with a 15 μm grain size is produced. What will be the yield stress of this sample?

Transcribed Image Text:

Yield Sample Stress 1/2 ID (mm-1) MPa) 24. 19 12 10 420 320 250 190