Steel shrinks when it gets hot. That's NOT Normal.

Video Description

G'day everyone, Taking a small break from machining again to go into an interesting property that steel has. And that is when it gets hot it shrinks.... Kinda. This only happens during a small temperature window at high temperatures, but this property is not common, as most materials will only expand when heated. Like last weeks video on heat treating, it all comes down to the microstructure. At elevated temperate the ferrite and perlite will rearrange themselves into austenite. The austenite is physically denser (due to the arrangement of the atoms in the lattice) going from body centered cubic to face centered cubic. I will try my best do demonstrate it through a basic ball and ring experiment which I do hope was done correctly. #machining #heattreatment