Alloy Cast Steel Rolls for Heavy Rolling Duties
LONSUN supplies alloy cast steel rolls for roughing, backup, vertical and universal mill applications. Grade selection is based on rolling load, required toughness, barrel hardness, pass duty, current roll performance and the operating risks of the stand.
Discuss Your Alloy Cast Steel Roll RequirementAlloy cast steel rolls have lower carbon content than Adamite, high-chromium steel and graphite steel rolls. They are produced from alloyed molten steel with controlled casting and heat treatment to provide toughness, mechanical strength, wear resistance and fire-crack resistance for heavy rolling conditions.
Alloy Cast Steel Grades and Applications
The published AS grade range covers several heavy-duty positions. Grades without a published application in the current table require direct confirmation against the drawing and stand duty.
| GRADE DIRECTION | PUBLISHED APPLICATION | COMMON REQUIREMENT | DATA TO REVIEW |
|---|---|---|---|
| AS40 / AS50 | Hot strip and hot plate roughing or backup rolls | High mechanical strength with application-matched barrel hardness | Load, torque, reduction, temperature, barrel duty and current campaign |
| AS60 / AS60 I | Section and bar roughing rolls; universal mill | Toughness and bite under grooved or universal-mill duty | Pass, groove depth, roll function, product mix, guides and cooling |
| AS65 | Hot strip roughing, backup and vertical rolls | Carry heavy load while controlling fire cracking and surface wear | Stand function, rolling force, temperature, scale, cooling and incidents |
| AS70 / AS70 I / AS70 II | Medium/light section, bar and wire-rod roughing duties | Stable roughing performance across long-product passes | Pass schedule, torque, reduction, stock temperature and current material |
| AS75 / AS75 I | Bloom/cogging, universal and hot-strip roughing duties | Match toughness, hardness and mechanical strength to severe load | Mill type, roll function, drawing, load spectrum and failure history |
AS65 I and AS70 II have published chemistry and properties but no specific application stated in the current table; do not assign them by similarity alone.
Material and Technical Reference
The alloy system and heat treatment establish the hardness and strength direction for each AS grade. Final grade selection must connect the published ranges to the actual roll function and acceptance specification.
Chemical Composition
| Symbol | C | Si | Mn | Cr | Ni | Mo | V | Nb |
|---|---|---|---|---|---|---|---|---|
| AS40 | 0.35-0.45 | 0.20-0.60 | 0.60-1.20 | 2.00-3.50 | 0.00-0.80 | 0.30-0.70 | 0.05-0.15 | - |
| AS50 | 0.45-0.55 | 0.20-0.60 | 0.60-1.20 | 1.00-3.00 | 0.00-1.00 | 0.30-0.70 | 0.05-0.15 | - |
| AS60 | 0.55-0.65 | 0.20-0.40 | 0.90-1.20 | 0.80-1.20 | - | 0.20-0.45 | - | - |
| AS60 I | 0.55-0.65 | 0.20-0.60 | 0.50-1.00 | 0.80-1.20 | 0.20-1.50 | 0.20-0.60 | - | - |
| AS65 | 0.60-0.70 | 0.20-0.60 | 0.70-1.20 | 0.80-1.20 | - | 0.20-0.45 | - | 0.06-0.10 |
| AS65 I | 0.60-0.70 | 0.20-0.60 | 0.50-0.80 | 0.80-1.20 | 0.20-0.50 | 0.20-0.45 | - | - |
| AS70 | 0.65-0.75 | 0.20-0.45 | 0.90-1.20 | - | - | - | - | - |
| AS70 I | 0.65-0.75 | 0.20-0.45 | 1.40-1.80 | - | - | - | - | - |
| AS70 II | 0.65-0.75 | 0.20-0.45 | 1.40-1.80 | - | - | 0.20-0.45 | - | - |
| AS75 | 0.70-0.80 | 0.20-0.45 | 0.60-0.90 | 0.75-1.00 | - | 0.20-0.45 | - | - |
| AS75 I | 0.70-0.80 | 0.20-0.70 | 0.70-1.10 | 0.80-1.50 | 0.20 | 0.20-0.60 | - | - |
Physical Properties and Published Application
| Symbol | Barrel Hardness | Roll Neck Hardness | Tensile Strength | Application |
|---|---|---|---|---|
| AS40 | 45-65 HS | ≤45 HS | ≥800 MPa | Hot strip mill backup roll, roughing roll |
| AS50 | 60-70 HS | ≤45 HS | ≥800 MPa | Hot plate mill roughing roll, cold rolling mill backup roll |
| AS60 | 35-50 HS | ≤45 HS | ≥650 MPa | Section mill and bar mill roughing roll |
| AS60 I | 35-45 HS | ≤45 HS | ≥750 MPa | Universal mill |
| AS65 | 35-45 HS | ≤45 HS | ≥650 MPa | Hot strip mill roughing roll, backup roll, vertical roll |
| AS65 I | 35-45 HS | ≤45 HS | ≥750 MPa | — |
| AS70 | 32-42 HS | ≤45 HS | ≥650 MPa | Medium section and light section mill roughing roll |
| AS70 I | 35-45 HS | ≤45 HS | ≥680 MPa | Bar mill and wire rod mill roughing roll |
| AS70 II | 35-45 HS | ≤45 HS | ≥700 MPa | — |
| AS75 | 35-50 HS | ≤45 HS | ≥700 MPa | Bloom/cogging mill roughing roll; universal mill |
| AS75 I | 35-50 HS | ≤45 HS | ≥800 MPa | Hot strip mill roughing mill |
Published values are reference ranges. Confirm hardness scale and location, heat-treatment condition, NDT, dimensions, machining and grade-specific acceptance criteria before production.
Heavy-duty roll symptoms often involve both mechanical and thermal factors. Review roll records together with load, pass, cooling, bearing and mill-event evidence.
| SYMPTOM | POSSIBLE AREAS TO CHECK | INFORMATION NEEDED |
|---|---|---|
| Excessive wear or poor bite | Grade/hardness match, scale, slip, reduction, surface condition and product mix | Pass, current material, tonnage, wear map, diameter and rolling data |
| Fire cracks | Thermal cycling, cooling interruption, local overheating, stoppage and incomplete crack removal | Crack map, cooling/event log, campaign, diameter and grind/NDT history |
| Barrel cracking or breakage | Overload, cobble, stress concentration, pass depth, material strength and internal indication | Fracture photographs, drawing, load/torque history, incident details and NDT records |
| Neck or fillet damage | Bearing/chock condition, alignment, fillet geometry, torque, bending load and handling | Damage location, drawing, bearing data, process event and inspection report |
| Uneven pass wear | Guides, alignment, top/bottom load balance, cooling distribution and pass design | Axial measurements, pass drawing, setup, photographs and product dimensional trend |
Safety note: barrel or neck cracks, visible spalling, abnormal vibration or noise, sudden 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 alloy cast steel 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 |