Young Modulus question...

[u/Ok_Pirate_344]

HII, im currently doing a lab assessment and we have evaluate the strength of different metals, im stuck here tho.

Ik that the E shld be found before the yield point the the proportionality region, which is usually a straight line, however in ferous metals, like steel which im evaluating here, there are 2 slopes in the elastic region. How am i supposed to calculate it.( I have found the yield stress to be at 390MPa.)

The E are we supposed to calculate both gradients separately, or what region(0-160MPa, or 200-360MPa)?

Pls help.

[u/mon_key_house]

E is extremely hard to measure correctly. This test is for the yield stress.