Forged Steel Rolls for Hot Rolling Mills
LONSUN supplies forged steel rolls for plate, planetary, welding-tube, seamless-tube and non-ferrous hot-rolling applications. Grade, barrel and surface hardness, hardening depth, toughness and machining are selected against the roll function and operating conditions.
Discuss Your Forged Hot Roll RequirementForged hot-mill rolls are produced from forged steel blanks and heat treated to develop the required hardness distribution and mechanical properties. Their selection must account for roll type, bite, load, temperature, wear, hardening depth and resistance to accidental damage—not nominal surface hardness alone.
Forged Hot Roll Grades and Applications
The current published application matrix links FSH-1 through FSH-7 to the following mill and roll positions.
| MILL TYPE | ROLL TYPE | PUBLISHED GRADE DIRECTION | DATA TO REVIEW |
|---|---|---|---|
| Plate mills | Primary rolls | FSH-1, FSH-2 | Roll function, reduction, load, temperature, bite and drawing |
| Planetary mills | Work, feed and backup rolls | FSH-4 for work rolls; FSH-1 for feed and backup rolls | Roll position, contact load, speed, cooling and current performance |
| Welding tube mills | Forming, sizing and vertical rolls | FSH-7 | Tube size, forming sequence, contact pattern, surface and dimensional requirement |
| Seamless tube mills | Extruding and straightening rolls | FSH-5/FSH-6 for extruding; FSH-7 for straightening | Process type, temperature, load, geometry, cooling and wear pattern |
| Non-ferrous plate and strip mills | Piercing, pushing-point, work and backup rolls | FSH-4, FSH-7, FSH-2/3 and FSH-3/4 by roll function | Alloy rolled, roll function, surface target, load, speed and lubrication |
The application matrix is a published direction only. Final grade, heat treatment and hardness distribution must be confirmed against the drawing and duty.
Material and Technical Reference
Forging reduction, alloy composition and heat treatment work together to establish toughness, barrel hardness, surface hardness and hardening depth. The following ranges should not be separated from the roll design.
Chemical Composition
| Symbol | C | Si | Mn | Cr | Ni | Mo | V | W |
|---|---|---|---|---|---|---|---|---|
| FSH-1 | 0.55-0.65 | 0.17-0.40 | 0.50-1.00 | 0.50-1.20 | ≤0.25 | 0.20-0.40 | - | - |
| FSH-2 | 0.55-0.65 | 0.20-0.40 | 0.60-1.00 | - | 0.10-0.30 | 0.10-0.30 | - | - |
| FSH-3 | 0.45-0.65 | 0.20-0.50 | 0.50-0.90 | 3.00-3.60 | - | 0.40-1.20 | 0.10-0.35 | - |
| FSH-4 | 0.60-0.80 | 0.30-0.80 | 0.40-0.90 | 2.50-3.50 | 0.40-0.50 | 0.20-0.60 | - | - |
| FSH-5 | 0.30-0.40 | ≤0.40 | ≤0.40 | 2.20-2.70 | - | - | 0.20-0.50 | 7.50-9.00 |
| FSH-6 | 0.32-0.43 | 0.80-1.20 | 0.20-0.50 | 4.50-5.50 | - | 1.00-1.60 | 0.30-0.60 | - |
| FSH-7 | 0.80-0.95 | 0.25-0.45 | 0.20-0.55 | 1.70-2.40 | - | 0.20-0.40 | ≤0.15 | - |
Published Barrel and Surface Hardness (HS)
| Hardness | FSH-1 | FSH-2 | FSH-3 | FSH-4 | FSH-5 | FSH-6 | FSH-7 |
|---|---|---|---|---|---|---|---|
| Barrel | 34-40 | 35-45 | 50-60 | 34-45 | 65-76 | 50-58 | 69-76 |
| Surface | 55-75 | 50-60 | 60-70 | 60-75 | 80-87 | 65-71 | 80-87 |
Confirm hardness scale, surface and barrel test locations, hardening-depth definition, heat-treatment condition, ultrasonic inspection, machining allowance and final dimensions before production.
Forged-roll performance depends on grade, heat treatment, hardening depth, roll geometry and operating load. Review mill and inspection data together.
| SYMPTOM | POSSIBLE AREAS TO CHECK | INFORMATION NEEDED |
|---|---|---|
| Rapid wear or poor bite | Grade/hardness match, surface condition, scale, slip, reduction and product mix | Roll function, campaign, wear map, diameter, roughness and process data |
| Thermal cracks | Thermal cycling, cooling distribution, stoppage, local overheating and grinding practice | Crack map, temperature/cooling data, event log and NDT/grind history |
| Spalling or surface damage | Crack growth, indentation, local overload, hardening-depth condition and internal indication | Roll ID, diameter, photographs, incident history and NDT result |
| Neck or fillet failure | Bearing/chock condition, alignment, fillet geometry, torque/bending load and handling | Drawing, fracture location, load event, bearing condition and inspection record |
| Runout or profile instability | Machining, straightness, thermal crown, bearing fit, alignment and uneven wear | Dimensional report, runout, profile measurements, setup and process trend |
Safety note: deep or growing cracks, visible spalling, neck distress, abnormal vibration/noise, coolant loss or a major overload event require action under the mill’s own safety procedure.
RFQ and Procurement Checklist
A complete RFQ reduces repeated clarification and prevents the quotation from being based only on size and hardness. The buyer’s data and the supplier’s confirmation should form one technical-commercial baseline.
| RFQ ITEM | BUYER PROVIDES | LONSUN CONFIRMS |
|---|---|---|
| Drawing and dimensions | Drawing revision, barrel and neck dimensions, fillets, grooves or pass details, and mounting features | Manufacturing scope, tolerances, machining, working layer where applicable, and drawing exceptions |
| Mill and application | Mill type, stand, roll function, rolled product, steel grade and pass | Proposed forged hot-mill grade, hardness and application basis |
| Operating conditions | Rolling force, torque, reduction, speed, stock temperature, cooling and lubrication where used | Material direction, key operating risks and inspection conditions |
| Current performance | Current roll material, hardness, campaign, wear, grinding and incident history | Comparison basis, evaluation method and technical risks to monitor |
| Quality documents | Required chemistry, hardness, microstructure, NDT, dimensions and third-party inspection | Test method, coverage, acceptance criteria and document list |
| Commercial requirement | Quantity, destination, required delivery date, packaging and Incoterm | Price basis, production scope, delivery basis, packing and quotation validity |