Steel & non-ferrous Industries
In steel & non-ferrous industries, bearings can be found in a vast range of plant and equipment that is used in both upstream and downstream processes: from the storage yard for raw materials to the steelmaking, rolling and refining processes.
The operational environment for these bearings is unique to steelmaking, comprising particle contamination, water and heat. In addition, the bearings may have to cope with heavy or shock loads and vibration, operational speeds ranging from extremely slow to extremely high, coupled with rapid acceleration and deceleration. This makes for a demanding operational environment that is not found in other applications.
We offer a comprehensive range of bearings for the steel industry, from standard bearings to our own independently developed, high-capacity specialised bearings. NSK is also responding to the need for high added-value products and an environmentally friendly approach.
Sintering Plants
Operating conditions: High temperatures, heavy loads, low speeds and contamination
Sintering plants have various requirements and problems which demand specific solutions. For example, bearings for pallet wheels and inboard rollers (plain bearings) often fail prematurely because sinter particles penetrate the bearings. This contamination, coupled with thermal effects, can cause premature lubricant failure. Grease escaping from the bearing can also contaminate the areas surrounding the machine. Frequent re-lubrication results in high operating costs and is harmful to the environment.
Total Quality Solution:
NSK roller bearings boast a service life which is up to three times as long as standard bearings.
Instead of a plain bearing, a roller bearing with a special seal is used. The newly developed encapsulated construction effectively prevents scale from penetrating into the bearing. The high quality grease also has outstanding resistance to heat and pressure. Re-lubrication of the bearing units is unnecessary, keeping the area around the machine clean.
Our Innovations:
Sealed-Clean Bearings for Sintering Pallets
BOFs and Bessemer Converters
Operating conditions: High temperatures, heavy loads, extremely low speeds and oscillations
A typical problem for bearings in Bessemer converters: the swivel bearing cannot be replaced without dismantling the central wheel. This makes replacing the bearings time-consuming and drives up maintenance costs. The downtime can cause production stoppages in downstream processes.
Total Quality Solution:
NSK split bearings prevent stoppages
To solve this problem, engineers from NSK have developed split bearings with an outer ring, an inner ring, a roller and cage set, and a locking ring which incorporates the seal sliding surface. This allows bearings to be changed without removing the central wheel, reducing maintenance costs and shortening downtimes while bearings are replaced.
Our Innovations:
Ultra-Large Split Bearings for BOF
Continuous Casting Machines
Operating conditions: Heat, heavy loads, steam (water spray), extremely low speeds, scale and skewed positioning
Differential speeds in the roller/raceway contact zone can cause uneven wear in spherical roller bearings. Spalling and cracks on the raceway of the outer ring are costly as they cause unplanned production stoppages and above-average consumption of bearings.
Total Quality Solution:
NSK bearings enable considerably longer service lives.
To tackle this problem, NSK has developed bearings with reliable materials and special constructions. The chemical composition of the steel used, patented heat treatments and carefully checked optimum retained austenite content all make SWRTM bearings extremely wear-resistant, resulting in significantly longer service life.
NSK also offers the “RUB” bearing series which consists of cylindrical roller bearings with a self-aligning outer ring (floating bearings). The “RUB” design prevents wear and therefore stoppages because there is no differential speed in the roller/raceway contact zone. Also available is the newly developed “AR” series, a range of taper roller bearings with a self-aligning outer ring (fixed bearings).
Our Innovations:
SWR™ Spherical Roller Bearings for Use in Continous Casting
Cylindrical Roller Beaings with Aligning Rings for Locating Position
Taper Roller Bearings with Aligning Rings for Locating Position
Long-Life Split Cylindrical Roller Bearing Units
Rolling Mills
Operating conditions: Wide-ranging speeds, heavy loading from rolling forces, oscillations, shock loading and high temperatures, penetration of scale and water
Grease lubricated rolling mills such as hot strip, skin pass, cold rolling and finishing mills use large quantities of grease. Insufficient lubrication can quickly lead to premature failure. In addition to this, the operating conditions mean that foreign matter and moisture frequently contaminate the bearings. This results in spalling, seizure, high bearing consumption costs and unplanned stoppages on the production line.
Total Quality Solution:
NSK ultra-pure steel for maximum reliability.
NSK offers specific bearings for rolling mills which guarantee higher reliability and longer operational service lives. Sealed bearings minimise the environmental impact and help reduce grease consumption. Ultra-pure steel (STF series) with optimum heat treatment prevents cracks and early raceway damage. In addition, NSK has developed WTF™ material (WTF™ series) for bearings which are exposed to water penetration. The four-row extra-capacity sealed-clean taper roller bearings (KVS series) are capacity-optimised, resistant to contamination by foreign matter and boast improved sealing performance. We offer these bearings in a wide range of materials to suit different operating conditions.
Our Innovations:
Super-TF
Super-TF Roll Neck Bearings
WTF™ Roll-Neck Bearings
Extra-Capacity Sealed-Clean Roll Neck Bearings
