Relationship between microstructure and strength in eutectoid steels

This paper analyzes the influence of the microstructural changes undergone by eutectoid pearlitic steels during continuous cold drawing on their yield strength. To this end, samples from a real manufacturing process (wire drawing) were studied, and consideration was given to the microstructure evolution as the drawing progresses up to the final commercial product which is heavily drawn and has undergone severe straining. It is seen that the pearlite interlamellar spacing (decreasing with cold drawing) influences clearly the improvement of yield strength (increasing with cold drawing, which is the final aim of manufacturing), although a relationship of the Hall–Petch type cannot be fitted in this case, probably because cold drawing produces not only an increasing closeness of the pearlitic packing, but also a microstructural orientation in the material.