^Breakage part of work roll: roll barrel
^How it looks like?
-Normally occurs in roughing stands. Generally speaking, breakage happens after less than 10 pcs of steel rolling from beginning of work roll change, and more likely to happen in winter.
-Fracture surface shows a radial direction from hub to barrel surface.
$See pic as below:
^Why this happened?
-Caused by Max temperature difference between barrel surface and hub. Over-high temperature difference normally caused by temperature of barrel surface climbing up too fast, due to lack of cooling water during the steel rolling process.
We Kaida Roll suggest:
-Roll pre-heating, particularly in winter, meaning work rolls shouldn’t be colder than room temperature,
-small output at the begging of rolling process, then gradually increasing rolling steel output until reach a stable temperature difference of the barrel cross section.
-Keep adequate cooling water