Hardening and Tempering

SFS has two body hardening methods. One is Dual Frequency Progressive Induction Hardening and the second is Multi-zone Microprocessor controlled Gas-fired Hardening.

Five dual coil progressive induction hardening units provide frequency combinations of 60/100, 60/600, and 600 cycles. One of which is the largest in North America with capacity to 1140mm Diameter X 7620mm OAL. All work rolls and some smaller backup rolls can be hardened on these induction units. In addition to the progressive water quenching located below the induction units. In addition to the progressive water quenching located below the induction units, there are two cryogenic quenching units that are able to rapidly cool the roll to -85°C, using liquid nitrogen. This additional setup allows for the maximum reduction of retained austenite achieving the highest possible hardness.

SFS has 3 Selas gas fired furnaces, with the maximum diameter capacity of 1700mm. Multiple quenching stations provide radical water, air, mist, and forced air quenching. When coupled with multiple tempering cycles SFS has the ability to establish the ideal microstructure to meet the rolling conditions of backup rolls in the mill environment.

Through SFS’ advanced refining, hardening, and quenching and tempering techniques, our finished rolls can ideally meet the customer’s hardness requirements, and achieve the deepest hardness layer with optimal hardness uniformity.

Our third goal is to achieve the tightest dimensional tolerances and optimal surface finishes. The direct benefit of this achievement, to our customers, is the precision finish of rolled products.

Our finishing department adheres to strict tolerances as an integral part of our quality assurance program. Most of our finishing machines are CNC equipped. The capabilities are as follows:

  • Lathes: up Φ1900mm; Maximum length: 7620mm; Maximum Weight: 100Tons
  • Grinders: up to Φ1700mm; Maximum length: 7620mm; Maximum Length: 100Tons
  • Sawing Machines: up to 1020 mm2
  • Boring Lathes: up to Φ2500mm; Maximum Length: 45mm
  • Horizontal and Duplex Milling Machines: up to 1700mm
  • Crane: up to 200 metric tons

Our machining equipment produces accurate and consistent finishes in accordance with the manufacturing drawing. Using our precision finishing capabilities, a TIR of ±2.5μm (±0.0001″) is routine.