Advanced technologies improve roll performance

RollguardTM overlay services and technologies

Utilizing top-quality special alloy overlays and state- of-the-art roll cladding technology, SMS group Inc. provides complete roll manufacturing and reconditioning services for all types of caster rolls from true casting, zone and bender segment to run- out, solid one-piece, sleeves-on-shaft or split--design rolls with both center-bore or peripheral-bore cooling. We also manufacture and recondition process line rolls, such as galvanizing line, furnace and zinc pot; down-coiler pinch and wrapper; leveler; hot strip tension; and table, cradle, bridle and looper rolls.

Precise processes

Because our roll overlay facilities are ISO-certified, our RollGuardTM processes adhere to strict quality plans; drawings are controlled; inspection and measuring equipment is precisely calibrated; and our testing and inspection personnel are highly qualified. To insure quality repairs, our welding, roll cladding and technical experts develop precise procedures and accurately detail materials and specifications.

Extensive arc-cladding options

SMS group Inc. provides the full range of ferrous and non-ferrous roll cladding, custom tailored to your specific roll application. Our rigorous process for identifying the combination of buildup and overlay materials best suited to your application adds value by extending roll life and product quality. In fact, our RollGuardTMoverlays frequently perform better and last longer than the OEM roll cladding.

We can clad rolls using any combination of submerged-arc, gas-shielded metal arc, gas-tungsten arc or open-arc overlay technologies. Our open-arc technology reduces heat input and can extend roll life by improving resistance to cracking, corrosion, wear and pitting. We also use in-house thermal-fatigue simulation testing to insure claddings will provide superior performance.

Advanced electro-slag strip overlays

Depositing a strip up to 60-mm-wide, our Electro-Slag Welding (ESW) process provides a superior hard-faced surface for reconditioning hot strip mill rolls.

Our ESW process is not an arc process: the sintered strip and the roll surface are melted with heat gener- ated by slag resistance to electric current. Because the ESW welding process has the lowest dilution of the base metal, neutral flux and a large liquid pool, overlay chemis- try and hardness is extremely homogeneous. As a result, rolls that have been clad with our ESW strip process have better wear profiles and longer service lives and runs between regrinds.

Submerged-arc strip overlays

Using our Submerged-Arc Welding (SAW) strip welding process and overlays up to 60-mm-wide, we can resurface long-bodied continuous caster rolls and table rolls. Compared to submerged wire-arc overlays, our SAW overlays have longer surface lives. And because it is a strip welding process with fewer overlapping areas, inter-bead and reheat regions, the likelihood of defects is significantly reduced.

Advanced electro-slag strip overlays

Depositing a strip up to 60-mm-wide, our Electro-Slag Welding (ESW) process provides a superior hard-faced surface for reconditioning hot strip mill rolls.

Our ESW process is not an arc process: the sintered strip and the roll surface are melted with heat gener- ated by slag resistance to electric current. Because the ESW welding process has the lowest dilution of the base metal, neutral flux and a large liquid pool, overlay chemis- try and hardness is extremely homogeneous. As a result,

rolls that have been clad with our ESW strip process have better wear profiles and longer service lives and runs between regrinds.

Submerged-arc strip overlays

Using our Submerged-Arc Welding (SAW) strip welding process and overlays up to 60-mm-wide, we can resurface long-bodied continuous caster rolls and table rolls. Compared to submerged wire-arc overlays, our SAW overlays have longer surface lives. And because it is a strip welding process with fewer overlapping areas, inter-bead and reheat regions, the likelihood of defects is significantly reduced.

Superior overlay chemistry, wear profiles

Because our ESW and SAW strip-cladding processes achieve the exact required coating chemistry in the second overlay layer, they provide more usable clad- ding and better wear profiles, which means longer roll service life, less frequent roll changes and reduced maintenance costs.

Comprehensive RollGuardTM services

Because achieving optimum cladding properties can rely on post-weld heat treatments, we also maintain in-house heat-treating furnaces in all of our cladding facilities.

With modern CNC tools, we machine rolls to the exacting tolerances required by today’s casters, rolling mills and finishing facilities.

Our comprehensive roll services include: welding, material science and metallurgical evaluation; technical and failure analysis; welding design; value- added roll performance analysis tracking programs; and consulting services.

Rolling mill roll maintenance

SMS group Inc. can expertly maintain backup and work rolls used in hot and cold rolling mills. Undetected surface cracks and bruising can cause rolls to spall or break in the mill stand. To insure defective rolls don’t return to service, we use a roll inspection system with ultrasound and eddy current testing equipment that measures both surface and subsurface defects.

After removing all cracks and defects, rolls are accurately ground to your specifications to ensure optimum performance, minimize stock loss and maximize roll service life. Our twenty-first century grinders can precisely maintain your roll’s taper, crown and size specifications.

Because today’s markets demand sheet products that are rolled to exact dimensions, we also inspect chocks and bearings to insure proper tolerances are maintained and report discrepancies so repairs can be made. Bearings assemblies are also removed from the chocks, cleaned, inspected for defects and measured; end play is adjusted if needed; load zones are rotated; and bearings are reinstalled into the chocks. Finally we carefully reassemble rolls and chocks to manufacturers’ or mill specifications; verify all assemblies; and provide verification reports.

Rolls and roll assemblies are also tracked by our Roll Tracking System that integrates grinding and mill production data to evaluate equipment performance. Combined with equipment cost information, our system helps you identify rolls and bearings that perform better, last longer, provide better quality product—and provide the best return-on-investment.

Electro-discharge work roll texturing

Sheet producers under pressure to produce flawless sheet for automotive and other demanding applications know that texture on work rolls is critical because it’s transferred to the sheet being produced. Electro-Discharge Texturing (EDT) is a specialized texturing process that replaces shot blast and provides a superior surface texture on rolls prior to chroming. It produces consistent, repeatable surfaces with tight tolerances from 50-350 Ra, extremely uniform surface with little variance over the surface of the roll and superior textured surfaces on hard work rolls.

Using proprietary EDT equipment, designed and manufactured by SMS group Inc., we can uniformly texture the entire roll surface, with no gaps on the ends. And our EDT equipment also removes grind chatter while texturing to produce dependable rolls that consistently deliver quality sheet.

Work roll chrome plating

At our Warren, MI workshop, we can expertly chrome plate work rolls. Chrome is a superior coating for rolls: it is one of the hardest metals, has excellent corrosion resistance and low coefficient of friction. This combination of hardness and low coefficient of friction results in very high wear resistance. Consequently, chrome plating can extend roll life up to four times. Rolls that used to wear out in about three hours can last up to 12 when they are chrome plated. This increase in roll life lowers operating costs, reduces downtime. Our 24/7 maintenance operations also reduce downtime. Often rolls picked up in the morning for chroming can be back in your mill, ready- to-roll, the same evening.

With more than 60 years experience applying chrome plating, we have the know-how to chrome rolls so they consistently provide superior performance. Plus rolls that have been pre-treated with our proprietary technology have longer service lives and experience fewer problems.

Roll shop management

SMS group Inc. can provide turnkey shop operations and manage roll maintenance shops for hot and cold rolling mills. Depending on your needs, we can provide a complete roll shop with equipment and staffed with our trained technicians or manage your shop, equipment and personnel. In addition to maintaining rolls and inspecting chocks, using our proven management system, we manage your roll assets by carefully monitoring remaining roll life and production per roll. Detailed analysis of roll history identifies cost-effective top performing rolls—and poor performers.

We have provided roll shops for single-stand plate mills, seven-stand hot strip and four-stand cold strip mills. With our roll maintenance shop services, you can better manage and reduce your rolling mill costs, improve your product and minimize downtime. We can also eliminate the high initial-cost of establishing a shop and fixed employee costs providing you with more flexibility to fluctuating market demands.

Galvanizing line and furnace roll maintenance, coatings

SMS group Inc. repairs and restores galvanizing line, furnace and zinc pot rolls so they perform like new. We can also precisely machine and resurface rolls, remove dross and replace zinc pot bearing systems.

Superior RollGuardTM coatings

Marketed under our RollGuardTM brand, we are
the exclusive US supplier of high-performance coatings, applied with a state-of-the-art thermal spray technology developed by Tocalo Co., Ltd., of Japan, that can extend the service life of zinc pot and furnace rolls significantly and improve steel strip product quality.

Sink and stabilizer rolls in zinc pots are prone to dross pick-up and need to be protected from molten zinc and their surfaces kept smooth so the sheet produced is free from surface defects.

A variety of boride and carbide alloy coatings applied with our thermal spray equipment is the answer.
This system produces dense coatings that have exceptional hardness and high compressive and traverse rupture strength. As a result, because rolls coated with our RollGuardTM system have high wear resistance; long service lives; and greatly increased resistance to corrosion, wear and zinc-dross adhesion, they produce galvanized strip with superior surface quality.

Superior performance for you

To learn more about how SMS group Inc. can help you improve your roll performance, call us at 724-553- 3420 or send an email to Info.TechnicalServices@SMS-group.com. We have the advanced roll maintenance technologies to help you achieve your quality and productivity goals and operate more efficiently and profitably.