Heat Treating

A little thing:
At 1:25, the bonds does not brake all at once like that. The matrix deforms and that's only one bond (on that view) that brakes and then it relink with the adjecent atom, deforming the matrix and braking the adjecent bond. Like that, the braked bond "travels" trought the cristal. That makes it easier to understand why a little inclusion or an alloy induced deformation on the matrix cam make the metal harder.
I hope i helped.

But don't the carbon atoms add extra tension to the bonds, making the bonds break sooner?

To understand that you need to get familiar with the concept of dislocations. Dig it at wikipedia if you want. The movment of dislocations does the braking and relinking i talked about. Inclusions and alloying elements make it harder for a dislocation to move because they create a tension field inside the material. If you have a lot of them and the dislocations cant move much, the material will brake rather than deform.

wait but that kind of went on a tangent, it was leading up to why heat treating would align the crystal structures, but instead talk about fortifying the structures through alloy.

-hero

good video, but its not about heat treating.

great stuff...

Alot less boring than the 25minute oldschool version!

cool video...it was so fruitful for me,thanks

So, how did 'heat treating' (the title of this video), add carbon to the matrix?

The title is a little misleading, maybe the full version on their site goes back to the topic of heat treating after this digression. Anyway, to answer you, carburizing (or case hardening) is the heat treating that adds carbon into the steel (or iron) but usually it is used to increase strenght/hardness of the surface layer of steel manufacts like gears and large bearings