STEEL SURFACE TESTING Smooth operator
High-quality roll surface texture imparted by the work roll to the strip is essential for good surface quality and has a big influence on the behaviour of the sheet during subsequent pressing, painting and coating operations. Andy Pye finds out how Tata Steel Packaging keeps on top of the problem
conditions to which steel rolls are subject being processed, prolonged use can have a detrimental effect on surface texture. Tata Steel Packaging’s CNC grinders with their
T
on-board automatic crack detection systems can work with pieces up to 3mlong and weighing 3-25 tonnes. “Precision grinding is a critical aspect of roll
refurbishment texturing and the grinding process must be completed in a very precisemanner to achieve the high quality finish needed,” says Kevin Thomas, roll shop section leader at Tata Steel Llanelli. “We searched themarket for a surface finish tester that would improve on the features of the instruments we were then using.We found the answer in the Surftest SJ-210 fromMitutoyo,” he added. When in service, regular surface finish
measurements taken with this device enable Tata Steel Packaging’s rolls to be inspected and withdrawn fromservice before they reach their surface finish performance limit, and replaced by refurbished ones. The worn rolls are then reground and re-inspected. Given theminimumstock removed in each grinding process, the rolls can go throughmultiple refurbishment cycles. “Before wemade our choice, we performed in-
depth gauge R&R studies to determine the accuracy and repeatability of theMitutoyo tester when used by our operators,” adds Thomas. “We also compared factors such as ease of use, robustness and battery life, against the instruments we were currently using.” Complying with the relevant industry standards applying to surface texturemeasurement,Mitutoyo’s
50 /// Environmental Engineering /// December 2017
The Mitutoyo’s ability to operate independently of mains power is a bonus in a plant of Llanelli’s size
ata Steel Packaging in Llanelli, South Wales, supplies light gauge steel in various widths, gauges and with an assortment of applied coatings, including tinplate and tin-free steels. Given the extremely harsh
Surftest SJ-210 is designed to be a robust, handheld tool that can be easily carried and used on site. A simple key layout provides users with easy access to the Surftest SJ-210’smultiple functions, while a high-visibility, colour-graphic LCD with a backlight provides excellent readability in all lighting conditions and displays assessed profiles and graphical data. “Now in constant use, given the size of our plant,
it helps that ourmultipleMitutoyo portable surface roughness testers are able to operate independently ofmains power and to take accurate surface measurements on any part of our rolls when in use, and also on our rolls when being reground. In addition, the instruments are in constant use inspecting the surface quality of the strip that we produce,” says Thomas. The Surftest SJ-210 boasts advanced data storage
capabilities, up to 10 setups and onemeasured profile can be stored in the unit’s internalmemory. An optionalmemory card can be used to further expand the tester’smemory and to enable the storage of large numbers ofmeasured profiles and setups. If required, data can be transferred to and froma computer via a high-speed USB interface. In addition to calculation results, the compact
instrument can display sectional calculation results and assessed profiles, load curves and amplitude distribution curves. Access to each feature can be password-protected, which prevents unintended operation and enables settings to be protected. “As part of our stringent quality regime, to ensure
that ourMitutoyo Surftest SJ-210’s remain accurate, we calibrate each of themon a daily basis against a calibrated and traceablemaster,” Thomas concludes. “Although we only use Ra and Rz surface roughness parameters, the Surftest SJ-210s is future-proof as, if ever we need to test in other parameters, our Mitutoyo instruments are able tomeasure a wide range of surface roughness parameters.” EE
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
