With operations in 26 countries Tata Steel is one of the world’s most geographically diversified steel producers. Based in Glamorgan, South Wales, Tata Steel’s Port Talbot plant is capable of producing nearly 5 million tons of steel slab per annum and is the largest steel plant in the UK and one of the largest in Europe. From construction machinery and bridges, to filing cabinets and fridges, the steel made by Tata in Port Talbot is used across a wide range of end products. In addition, the automotive industry is a major user of steel-strip manufactured in Port Talbot.
As the application of the correct surface finish characteristics enables paint and various other coatings to successfully adhere to vehicles’ bodywork, the steel strip supplied by Tata steel to its global automotive customer base conforms to strict surface finish specifications. To ensure the consistent supply of first-class steel strip with the specified surface finish standards regular quality control checks are carried-out.
Given the large volumes of steel strip samples that needed to be checked to ensure conformity, in accordance with Tata Port Talbot’s quality policy and the business’ pursuit of further efficiencies, a search was recently made for an automated surface finish testing system. The answer was found in a bespoke machine that was designed and installed by Mitutoyo Gauging Technology.
Tata Steel Port Talbot, Section Manager Testing, John Lovegrove explained. “Although our previously used manual surface finish testing method delivered accurate results, it was extremely laborious and at times we struggled to keep-pace with the amount of surface finish tests that we needed to make. In addition, we needed to manually input each individual test result into our computer.”
“Having decided that we needed to source a highly-efficient, automated testing system we approached three companies with a list of system requirements. Not only did the staff of Mitutoyo Gauging Technology quickly understand our needs, they also suggested several additional improvements to our wish-list that would bring additional benefits. Also, as the project evolved and we realised the potential of the new custom-built tester, we asked for couple of further design tweaks that the Mitutoyo staff incorporated.”
“Now installed and fully operational, as our bespoke Mitutoyo machine performs rapid, very accurate surface finish tests on both sides of our strip samples in a single-pass, it has slashed our inspection times. Also, as our surface finish testing is now a fully automated process, after loading a large batch of samples into the machine, the operator concerned is able to perform other duties whilst our new tester operates unattended.”
“In addition to drastically reducing our surface finish testing times, as all relevant inspection data is now automatically downloaded, our new Mitutoyo system has also removed the potential for errors when inputting inspection data.”
Designed by the staff of Mitutoyo Gauging Technology in cooperation with Tata Steel personnel, in addition to being ideal for Tata Steel’s current use, the flexible surface finish measuring machine was devised in such a way as to remain ‘future proof’. For example, if Tata Steel’s requirements change, the bespoke aspects of the machine can be modified at a future date. Also, the system’s SJ-310 Surftest instruments are able to provide reading in a multitude of alternative surface finish parameters.
The two advanced Surftest SJ-310 precision surface roughness measurement instruments used in the machine provide an extensive range of measurement and analysis features. The advanced Mitutoyo instrument allows users to store up to 10 measurement conditions within its internal memory, whilst an optional memory card enables the storage of 500 measurement conditions. To avoid unintended operation and to prevent accidental changes to settings, all critical functions can be password protected.
Now, after a batch of 120 steel strip samples are loaded into the machine’s magazine, a vacuum griper picks up each sample in turn and moves it to the measuring station. The machine’s two Mitutoyo SJ-310 Surftest instruments then perform simultaneous, highly-accurate surface finish measuring routines on the upper and lower surfaces of each sample.
Although the vast majority of the inspection routines result in a positive result, on the rare occasion a negative result is found, rather than being automatically transferred to the dedicated ‘pass’ container, sub-standard samples are moved to a ‘fail’ location. This automated test cycle is then repeated until the entire batch of samples is accurately inspected. As the system is able to provide an early warning when samples’ surface finish parameters are drifting from their nominal conditions towards their bottom limits, all relevant information can be quickly communicated to Tata’s strip production department so that scrap situations can be avoided.
Mitutoyo Gauging Technology General Manager, Simon Elliott added. “Mitutoyo Gauging Technology is dedicated to providing our customers with high-quality, cost-effective bespoke metrology systems for applications that cannot be satisfied by the use of off-the-shelf products.”
“Following our liaison with John Lovegrove of Tata Steel, the resulting, highly-efficient, automated surface finish measuring machine was schemed, designed, built, tested delivered and commissioned within the required time scale. Although the machine was designed to provide ease of operation, to ensure that it was quickly brought into operation, soon after its installation we also provided operator training.”
“All at Mitutoyo Gauging Technology are delighted that the automated Tata Steel surface finish testing machine has proved so successful.”