New method for 3D surface inspection has convinced steel giant
18/12/2013
A major Turkish steel producer is optimising the production of high-speed compatible rails with a method that has been developed in Austria. The method is based on laser light section technology, which facilitates the non-contact examination of surfaces that are still hot. Hence, defects in the surface structure can be detected at an early point in time in the production process. The technology works in real time and delivers a whole range of advantages: cost reduction, rationalisation and quality improvement, as well as improved work safety and clear-cut documentation. The DIRIS 3D HOT method was developed by Austrian company NextSense and is sold worldwide.Mistakes occur, even in steel production. Defects on the surface are especially exasperating. Trained personnel can easily detect them – but only once the just-rolled workpiece has cooled off. So, by the time the product is accessible for visual inspection, many more pieces with the same defect might have been produced. An innovative method from NextSense GmbH in Graz, Austria, puts an end to that – and is now being deployed on an industrial level for the first time by a major Turkish steel producer.
The new method is based on the so-called laser light section technology, a method of optical 3D measurement technology that allows for the calculation of a precise height profile. To take the measurement, a laser line is projected onto a mobile object. Shifts of the laser line caused by changes in the surface structure are registered by several cameras and converted by means of photometric calculations in 3D coordinates. Once the object has been completely guided along under the laser line, you get a complete height profile of the object. Christoph Böhm, Marketing Manager of NextSense, explains: “Our DIRIS 3D HOT method works on a completely non-contact and automated basis. The customer gets 3D data in real time, including the spatial depth of production errors as well as a complete documentation.” Hence, the method can be applied to surfaces that are still hot, such as those you have in steel production immediately after the rolling. This offers a whole range of advantages to users of the DIRIS 3D HOT method. Defects are detected very early in the production process and, once the cause has been eliminated, the production of large amounts of rejects can be prevented. In addition, the automated defect detection facilitates the classification of defects or other surface structures: chips, roll-ons, reefs or scales are detected as reliably as stamps and rolling marks. The performance of the method is immensely impressive: recesses of depths of merely a few tenths of a mm are detected and classified.
Automation of the surface inspection also improves work safety when dealing with hot steel products of over 1000°C, because cameras withstand the heat, not employees. Naturally, another great advantage is the complete documentation of the measurement results: objective 3D data in colour diagrams replace subjective assessments made by employees.
The many advantages have now convinced a leading steel producer in Turkey. Upon exhaustive examination of the method, the company decided to order a SURFILES DIRIS 3D HOT facility for the production of faultless rails. When it comes to train rails, quality requirements have been rising enormously due to the fact that more high-speed lines are being upgraded. Competitive production and the delivery of huge order volumes in some cases can only be guaranteed with highly-efficient production methods. The deal that has now been struck adds a success benchmark for the newly established ‘Surface Inspection & Profile Measurement Systems’ (‘SURFILES’) division of NextSense. Alongside the rapidly growing segment of portable profile measurement devices, ‘CALIPRI’, this multi-million contract has contributed decisively to the fact that the company has exceeded its mid-term company goal, namely the double-digit million turnover limit.
www.nextsense.at
