molybdenum crystals grow from the edge to the middle. Notice how some crystals after a short growth 'destroyed' by their neighbors. There is nothing like a cubic symmetry crystals of molybdenum. (Increase of 200: 1) Wanting to make full use of such steel properties such as hardness and strength, a metallurgist by the introduction of other alloying elements increases the difficulty experienced by the carbon atom at its entry into the crystal lattice of iron. After all, the atom can not just disappear from the iron. In steels containing from 0.05 to 1.0% carbon, the conversion of iron catches carbons literally "surprise". They have no choice but to remain partially in the iron lattice as foreign bodies, causing its deformation and thereby increase the hardness and hardening.