Question

2. A 0.2wt% C plain carbon steel is slowly cooled from 950oC to a temperature just slightly below

723 ^oC. Assuming that austenite is completely transformed:

(a) Calculate the weight percent of the micro-constituents and of the phases formed.

(b) Describe in detail the phase transformations that would have taken place during this slow

cooling sequence.

(c) Outline the essential differences between displacive and diffusional transformations in steels.

(d) Discuss the existing evidence in support of the hypothesis that martensite formation in plain carbon steels is a diffusionless based reaction.

Answer 1