On-line Profile measurement of Slab Edges

摘要

On-line measurement of slab width during continuous casting is important. By adding a scanning function to the width measurement sensors LIMAB has developed a system that provides complete edge data. This is important both for casting process knowledge and for downstream processing. The measurement system is located next to the roll-out table either before or after the cutter. The system can also be applied in other locations where edge profile measurement is of interest. The system communicates internally using CAN-bus and can be interfaced to other systems using I/O or network connections. The system is developed for steel mill environmental conditions and the sensors are protected by stainless steel cooling boxes purged by air ventilators. Measured properties are slab position, edge profile, slab width (in multiple points) and slab edge thickness. In combination with accurate speed and temperature information, length and "cold" measures can be presented as well. The system has a capability to measure slabs up to 700 mm thick slabs at 2000 mm distance from the sensors. One scan takes 250 ms and produces up to 500 measurement points. Improvements at the Hot Strip Mill at SSAB in Borlange include: 1. better set up of the roughing mill since they know how much mass they have to work with on each slab. 2. better cooperation with their slab supplier, they have facts about the slab and are not only estimating. 3. reduced waste production where coils are produced out of specification. Improvements at Siderar, San Nicolas in Argentina include: 1. increased width measurement and control. 2. improvments in the Random Adjust Mould 3. reduced waste production where coils are produced out of specification.