60% Alumina brick for steel bottom pour

[diskullman]

It is quite common for the runner brick for steel bottom pour bricks to have steel strapping (usually used for securing pallets) installed on the outer surface. It is usually added for strength. I would assume that when the molten steel is poured, the brick heats up, and the steel strapping expands at a greater rate than the brick, making the strap loose and useless. Can anyone explain why these straps are so important?

Russell Giuliano

 

[kenvlach]

The outer brick surface is ~1000 C cooler than the inner at the start of the pour. Depending upon the thickness of the brick & the pour duration, the outer surface might heat up 100 C, maybe?