ICDP Rolls for Finishing Stands and Thermal-Shock Service
LONSUN supplies alloy indefinite chilled cast iron rolls, also known as AIC or ICDP rolls, for long-product, hot-strip, plate, temper and Steckel mill duties. Selection is based on stand position, hardness, graphite response, surface requirement and the mill’s thermal and mechanical conditions.
Discuss Your ICDP Roll RequirementICDP rolls are generally centrifugally cast double-poured rolls with fine graphite in a high-nickel working layer. The graphite supports resistance to thermal shock, while composition and casting practice allow the hardness range to be adjusted for different duties. Final selection must balance wear, surface condition, thermal cycling and incident risk.
ICDP Grades and Stand Applications
ICDP is used in finishing and selected roughing duties where thermal-shock resistance and stable roll-surface behavior are important.
| APPLICATION AREA | TYPICAL ROLL POSITION | COMMON REQUIREMENT | DATA TO REVIEW |
|---|---|---|---|
| Bar and wire mills | Pre-finishing and finishing stands | Maintain groove or profile while controlling thermal cracking | Pass, speed, stock temperature, product mix, cooling and current wear |
| High-speed wire mills | Pre-finishing roll rings | Combine ring integrity, wear stability and thermal-shock resistance | Ring drawing, shaft fit, speed, pass, cooling and mounting method |
| Hot strip and temper mills | Final finishing work rolls; temper work and backup rolls | Support strip surface and stable campaign performance | Stand, strip grade, roughness target, cooling, load, crown and grinding |
| Wide plate and Steckel mills | Roughing and finishing work-roll duties | Balance wear, bite and thermal cycling across a changing product mix | Plate grade, width, reduction, temperature, reversing cycle and current performance |
The AIC I–IV grades represent published composition and hardness directions; final grade selection must be confirmed against the actual stand and drawing.
Material Structure and Technical Reference
Nickel, chromium and molybdenum ranges are adjusted with the casting route to obtain the required working-layer hardness and graphite response. The published tables below are order references rather than universal operating limits.
Chemical Composition
| Symbol | C | Si | Mn | Cr | Ni | Mo |
|---|---|---|---|---|---|---|
| AIC I | 2.90-3.60 | 0.60-1.20 | 0.40-1.20 | 0.70-1.20 | 0.50-1.00 | 0.20-0.60 |
| AIC II | 2.90-3.60 | 0.60-1.20 | 0.40-1.20 | 0.70-1.20 | 1.01-2.00 | 0.20-0.60 |
| AIC III | 2.90-3.60 | 0.60-1.20 | 0.40-1.20 | 0.70-1.20 | 2.01-3.00 | 0.20-1.00 |
| AIC IV | 2.90-3.60 | 0.60-1.50 | 0.40-1.20 | 1.00-2.00 | 3.01-4.80 | 0.20-1.00 |
Physical Properties
| Symbol | Barrel Hardness | Roll Neck Hardness | Tensile Strength |
|---|---|---|---|
| AIC I | 55-72 HS | 35-55 HS | ≥400 MPa |
| AIC II | 55-72 HS | 35-55 HS | ≥400 MPa |
| AIC III | 65-78 HS | 32-45 HS | ≥400 MPa |
| AIC IV | 70-83 HS | 32-45 HS | ≥400 MPa |
Confirm hardness scale, test position, usable working layer, shell/core acceptance, inspection method and final grade in the order specification.
Common ICDP Roll Problems and First Review
ICDP performance depends on material selection, casting quality, cooling, rolling conditions and grinding practice. Review the complete campaign record before assigning a cause.
| SYMPTOM | POSSIBLE AREAS TO CHECK | INFORMATION NEEDED |
|---|---|---|
| Rapid wear or poor profile retention | Grade/hardness match, product mix, scale, slip, load, cooling and grinding basis | Stand, pass, tonnage, wear map, diameter and stock removed |
| Thermal checking or fire cracks | Temperature cycling, cooling coverage, stoppages, cobbles and incomplete crack removal | Crack map, event log, cooling data, campaign and NDT/grinding history |
| Spalling or shell damage | Surface crack growth, indentation, local overload, shell/core condition and abnormal mill event | Roll ID, current diameter, photographs, event history, spall depth and NDT result |
| Strip or product surface marks | Roll roughness, oxide/debris, thermal crown, chatter, cooling and grinding finish | Defect pitch, product side, roll surface, roughness and process trend |
| Uneven barrel or groove wear | Spray/header alignment, guide setting, pass profile, load balance and stand alignment | Axial wear measurements, drive/operator-side photographs and setup records |
Safety note: visible spalling, deep or growing cracks, abnormal vibration or noise, neck distress, sudden coolant loss or a major cobble should be handled 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 ICDP 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 |