Question

Discuss the variation of tensile strength, elongation, Vickers hardness and fracture toughness with C (carbon) % for normalised carbon steels. Write 500 words

Answer 1

Normalized carbon steel behavior with % of carbon present:-

1. Tensile strength variation:-

As the % of carbon increases the tensile strength of the normalized carbon steel decreases. With the addition of carbon, leads to an increase in brittleness of normalized steel which is weak in tension. Because as the number of carbon atoms increases it leads to hindering in the flowability of the material and block movement and hence restricting the capacity to plastically deform leading to brittle failure of the steel.

Following diagram shown below shows the variation of tensile strength with % of carbon variation.

2. Elongation variation:-

It follows the same trend as that of tensile strength ie. with the addition of % of carbon in the normalized steel, its brittle increases, and hence its ductility decreases lead to reduce in elongation of the body. The same can be observed from the above diagram too. As the number of carbon atoms increases it leads to hindering in the flowability of the material and block movement and hence restricting plastically deformation.

3. Vickers Hardness Variation;-

With the increase in % of carbon in the normalized steel the toughness decreases but hardness increases and hence with an increase in carbon % the Vickers Hardness increased. Because as the number of carbon atoms increases it leads to hindering in the flowability of the material leading to an increase in hardness of the steel.

4. Fracture Toughness variation:-

Like tensile strength and elongation variation, fracture toughness variation follows the same trend ie with an increase in carbon % the toughness of normalized steel decreases. Because as the number of carbon atoms increases it leads to hindering in the flowability of the material and block movement and hence restricting the capacity to plastically deform leading to brittle failure of the steel, ie, steel loses its toughness property.