Question

4. In a tensile test, two pairs of values of stress and strain were measured for the specimen metal after it had yielded: (1) true stress = 250 MPa, and

engineering strain = 0.42; and (2)true stress = 300 MPa, and engineering strain = 0.98. Based on these data points, determine the strength coefficient and strain-hardening exponent. (8')

Fig: 1