2. Annealed low-carbon steel has a flow curve with strength coefficient of 75000 psi and strain-hardening exponent of 0.25. A tensile test specimen with a gauge length of 2 in. is stretched to a length of 3.3 in. Determine the flow stress and the average flow stress that the metal experienced during this deformation.

Flow stress = 9390Psi

Average flow stress = 4173.33Psi

Explanation:

Given:

Strength Coefficient = 75000psi

Strain hardening Exponent = 0.25

Gauge length = 2inches

Stretch length = 3.3 inches

Flow stress, Yf = 75000 * ln (3.3/2) * 0.25

Yf = 75000 * ln (1.65) * 0.25

Yf = 75000 * 0.5008 * 0.25

Flow stress = 9390Psi

Average flow stress = 75000 * 0.5008 * (0.25/2.25)

Average flow stress = 4173.33psi