申論題

4. Applications of ferrous alloys (9%):
With the aid of a stable phase diagram and a metastable phase diagram shown above, answer the following questions:

(c) You are requested to make a cast iron with volume percent of graphite in 14%. Additionally, the cast iron should consist of a martensite matrix where graphite is embedded. Calculate the proper carbon concentration, and describe the treatment necessary to produce such this microstructure. Assume densities of 7.87 and ferrite and graphite, respectively. (4%)