Upgrading slab descaler with Duroxite® overlay plates

When steel slabs are heated, a scale of iron oxide is formed on the surface. This scale must be removed before rolling to ensure it doesn’t stick to the steel. The removal is done from both sides of the slab with high-pressure water jets, operating at 250 bar.

The environment inside the descaler is very harsh. The water jets get mixed with the abrasive iron oxide and strike the inside surfaces, creating erosive wear.

The previous solution has been to cover the surfaces with tiles made of aluminum oxide. The joints between the tiles are weak spots. The water jets loosen the tiles, which leads to unplanned maintenance stops to remove the tiles from inside the descaler. Tiles have very long delivery times, which further complicates the matter.

SSAB has replaced the aluminum oxide tiles with plates of Duroxite^® 100, which has a hardfacing layer of extremely wear-resistant chromium carbides. It gives several advantages: The time between maintenance stops can be twice as long. It is a more cost-effective solution since the tiles are very expensive. Maintenance can be performed by SSAB’s own service personnel. 

Since the Duroxite^® plates can be bent, cut, and welded, it gives high flexibility. The plates can be used to cover both the enclosure’s flat and curved surfaces. The gaps between the Duroxite^® plates are not an issue, they can be joined together by welding with Duroxite^® welding consumables.