(Solved): (a) Explain briefly the ductile to brittle transition behaviour shown by some metals and alloys ...

(a) Explain briefly the ductile to brittle transition behaviour shown by some metals and alloys. (15 Marks) (b) A stainless steel bar $$200\mathrm{mm}$$ in length and $$10\mathrm{mm}$$ square cross-section was pulled in tension. i. If the tensile load is $$20\mathrm{kN}$$, producing only elastic deformation, calculate the resulting strain if the modulus of elasticity of the steel is $$200\mathrm{GPa}$$. (10 Marks) ii. If the yield strength of the stainless stcel is $$700\mathrm{MPa}$$, what is the maximum load this sample can carry before undergoing plastic deformation? (10 Marks) iii. The specimen fractured after applying an increasing tensile load when the final length of the specimen was $$244\mathrm{mm}$$, what is the ductility of the sample in terms of percentage elongation? (20 Marks) (c) Briefly describe the following corrosion processes: i. Crevice corrosion (15 Marks) ii. Pitting corrosion (15 Marks) iii. Galvanic corrosion (15 Marks)