Tata Steel Refines High‑Pressure Water Descaling with Micro‑Epsilon Thermal Imaging Cameras

Tata Steel has integrated Micro‑Epsilon’s thermoIMAGER TIM M‑1 and TIM 400 T1500 thermal cameras into its high‑pressure water (HPW) descaling pilot facility. The cameras, mounted above the descaling trolley, capture surface temperatures before and after scale removal, enabling precise assessment of descalability and heat loss relative to nozzle pressure, flow, and descaling speed.

HPW descaling removes oxide scale by spraying hot steel with moderate‑to‑high pressure water, using either stationary flat‑jet nozzles or rotary rotor descalers. The process targets loose to sticky, primary to tertiary scale while optimizing impingement, surface chilling, and water‑flow consumption to improve surface quality and reduce work‑roll wear.

Because the process involves steam, water, and scale debris within confined boxes, conventional temperature measurements are challenging. Infrared thermography offers a non‑intrusive solution, delivering data that supports robust, energy‑efficient descaling regime maps—particularly valuable for difficult‑to‑roll grades prone to ductility cracking or surface defects.

In partnership with the Steel Metal Institute in South Wales (SAMI – www.samiswansea.co.uk), Tata Steel revamped a HPW descaling rig to optimise the process. The unit operates in static or dynamic mode, handling hot or cold material from steel to simulation material. Reheated samples—typically 70 × 70 × 100 mm blocks—are carried at speeds up to 4 m/s. After descaling, the carriage stops and the sample is transferred to an Argon‑filled container to limit further oxidation.

All parameters (height, pressure, flow, temperature, etc.) are logged via a Windaq data‑acquisition system, and a sophisticated post‑analysis routine characterises descaling efficiency.

The thermoIMAGER TIM M‑1 uses a short 1 µm wavelength detector, ideal for harsh, steamy environments where high‑temperature emissivity errors are minimized. The TIM 400 T1500 provides a long‑wavelength perspective. Together, they assess descalability and heat loss across a range of nozzle pressures, flows, and speeds, informing production‑process regime maps.

Both cameras come equipped with two interchangeable optics (f = 25 mm and 75 mm) for flexible field‑of‑view and mounting positions. The included TIM Connect software supports linescan and continuous acquisition modes; linescan is particularly useful when viewing space is limited, enabling a complete image of the slab as it passes.

“The thermal measurements, combined with surface state monitoring during and after descaling and the use of a CCD optical camera, have enabled the development of key HPW descaling knowledge for direct implementation and optimisation of plant practices,” said Didier Farrugia, Scientific Fellow, Rolling Finishing & Measurement Department, Tata Steel RD UK.

Optimising yield—whether by reducing scale or metal loss during reheating, or by improving surface state and defect minimisation—delivers critical cost‑performance benefits for the steel industry, estimated at around £1 million for a 1 % yield gain.

Farrugia added: “The cameras have proven reliable and easy to use, including the ability to synchronise the two devices at specific locations for full temperature traceability. They are also being deployed in other areas of steel manufacturing.”

For more information on the thermoIMAGER TIM series, visit www.micro-epsilon.co.uk or contact the Micro‑Epsilon sales department at +44 (0)151 355 6070 or [email protected].