A single crystal of BCC iron is subjected to tensile stress of 100 MPa along the [001] direction. Which of the two slip systems ((211) –[ 111 ] or (321)–[ 111 ]) is going to yield first?

An iron specimen is plastically deformed in shear by 1%, and it has u dislocation density of 1 10 14 m/ m 3 Assume that the dislocation density did not change in the 1% strain of thisspecimen, the Burger's vector (b) is a 2 [1 1 1] the slip plane is (110). the shear stress isapplied to the (110) plane, and the lattice parameter of the BCC iron is 0.286 nm. Calculate the magnitude of the Burger's vector for these dislocations in iron. Calculate the average distance moved by the mobile dislocations as a result of the 1% shear strain.

Estimate the elastic and plastic strain at the ultimate tensile strength in the low-carbon steel specimen in Figure 6.16.

At the ultimate tensile strength. (a) The true stress is at its maximum. (b) The specimen always fractures. (c) The maximum load-carrying capacity is experienced. (d) The material yields.