Never too cold for the API tracker

v-probe application 3Steel Production (Flat Iron): Rollers alignment with the Laser Tracker

One of the world’s largest steel producers in the world uses the API tracker outdoors, mounted on a crane in all weather. The API tracker’s wide operating temperature range of 14 to 113 degrees ensures that it can work, and make temperature compensation adjustments, after just a short warmup period.

Arcelor Mittal is an international steel company, created in 2007 from the Mittal Steel Company and Arcelor. The company has about 60 production facilities in more than two dozen countries employing approximately 320,000 workers. Arcelor Mittal is, in all respects, by far the largest steel producer in the world and is one of the world’s leading international corporations. At the production site in Fos-sur-Mer (France) the API laser trackers are used for alignment of rollers in the flat iron production – but that’s not the only area where the company uses them.

The API Laser Tracker which easily fits in an average car trunk (including all accessories such as a Tri-pod for quick changes of location), provides the solution for many measurement tasks which previously could not be performed without accepting much higher cost or/and much lower accuracy. Guy Priaud, Reliability & Predictive Maintenance Manager at Arcelor Mittal in Fos-sur-Mer near Marseille: “We have been using our API Laser Tracker since mid-2005. It was purchased primarily to inspect the orientation of the rolls before reassembly in our hot rolling mill. In the past, the solution for this task required time-consuming measurement efforts.” Operating 24 hours a day, the cylinders of the hot rolling mill need to be replaced and refurbished regularly.

The working plant in Fos-sur-Mer – originally planned in the seventies and designed for an annual production of 8-9 million tons of steel – has a road network more than 50 km in length. Today 3,500 Arcelor Mittal employees (plus 1,500 employees from other companies) produce only 4.5 million tons of steel annually.

Mr. Descaves isone of four employees in the department, and is responsible for carrying out the measure-ments with the API Laser Tracker : “Due to the enormous size of the plant, Laser Trackers are mostly trans-ported by car. The portability of the entire system has been the main reason for the selection. However, we didn’t look for the smallest system when we started with this project. We invited vendors from the best known laser-based measurement systems and in the end we had three detailed system presentations. Our main focus has been measurement repeatability and dynamic measurements. One competitor’s system crashed multiple times and the other one was too heavy for us. Because we have to measure on a 40m crane at the Arcelor-owned port facility, piggybacking the tracker to the extension arm was the best option.”

With a sensor weight of only 8.5 kg, the API Laser Tracker weighs considerably less than its challengers, and has a much greater measuring distance (up to 120 m range) than comparable systems, although the full range isn’t needed at Arcelor. Mr Descaves: “Our measurements are limited mainly to parts or systems of less than 20 meters. But for this we need a system that can operate over a wide temperature range – the measurements on a crane took place at outdoor temperatures of -2 degrees.”

The API Laser Tracker doesn’t require any active temperature compensation because of its construction principle; it has no fan and totally enclosed housing. It takes about 15 minutes for the tracker to adjust to the outdoor temperature.

At Arcelor Mittal, the laser tracker mainly takes over tasks that were previously assigned to theodolites. But it is not only the considerably higher accuracy of the laser tracker which has led to the replacement of conventional systems. “The main selling point is that immediately after the measurements are taken, all results are available in the form of test reports and graphical data which allows for a deep understanding of the measurements.” Three employees at Arcelor have been trained to use Metrolog software with the API Laser Tracker. The measurements are usually carried out by two employees.

Measurements are not only taken at the Arcelor plant in Fos-sur-Mer. More and more measurement tasks take place at the suppliers facilities to control the quality and accuracy of produced “as ordered“parts, even before they are delivered. Mr Descaves: “Not all suppliers currently have the ability to measure parts with the accuracy that we can accomplish using our new Laser Trackers. By measuring at the local suppliers factory, we avoid unnecessary and time-consuming returns and we are sure that the parts will meet our specifications.” Over time, the need

Over time, the need for inspection measurements, for a wide range of applications in the hot rolling mill, got numerous. Many companies are using service providers equipped with mobile measurement equipment for jobs on large parts or constructions, but with the level of Arcelor Mittal’s needs , it was far more cost effective to purchase their own Tracker. Guy Priaud: “Back in 2006 we used the API Laser Tracker for various measurement tasks for more than 70 days. The payback of this investment has already been achieved by the measurements of the rolls. For this measurement job, we now need only half the time previously required. We use the API Laser Tracker today in many ways throughout our company.”

Tasks can now take place anywhere on the factory premises. Even if new machines or equipment will be installed at the Arcelor Mittals plant, Priauds employees are sometimes asked for support. This happened, for example, with a new feeding system for the hot rolling mill. Contrary to expectations, the Italian manufacturer was not able to get the installation under control in Fos-sur-Mer. Priauds employees marched up with the API Laser Tracker and solved the problem on the spot.

In summary, the API Laser Trackerat Arcelor Mittal has now taken over a lot more tasks than those for which it was originally intended. The reason for this is the fact that the portable measuring system can be transported very easily to every location. After a quick setup the test readings are available. The achieved accuracies as well as the achievable operating distances surpass the current requirements. With these reserves, Arcelor Mittal feels on the safe side, since demands are likely to increase in the future.