ENGINEERING PROTOTYPE · V5.4

Multi-Pass Reduction Planner

Find the minimum feasible pass count, favor larger reductions early, and taper pass loads toward the final pass while respecting all mill limits.

Steel grade

Raw thickness (mm)

Target thickness (mm)

Strip width (mm)

Initial cold work (%)

Mill Data

Roll stand and equipment limits

Work roll diameter (mm)

Maximum roll force (kN)

Force safety margin (%)

Mill modulus (kN/mm)

Max line speed (m/min)

Driven rolls

Drive and coiler motor ratings

Rated power: mill motor & EACH coiler (kW)

Mill motor rated torque (kNm)

Mill motor base speed (rpm)

Mill motor maximum speed (rpm)

Mill motor overload factor

Overload duration (s)

Gear-specific limits

Gear	Ratio (motor:roll)	Max speed (m/min)	Entry tension (kN)	Exit tension (kN)	Efficiency (%)	Roll torque limit (kNm/roll)
Gear 1
Gear 2

The 1,000 kW rated-power limit is applied individually to the rolling drive, entry coiler and exit coiler at threading and running speed. Coiler mechanical power is estimated as |tension × strip speed|, assuming unity coiler efficiency; electrical/regen and acceleration allowances are not yet modeled. Motor overload is not credited for continuous rolling. Drive torque: the 30 kNm torque rating is available at low RPM; the 1,000 kW power limit reduces available torque above the true torque/power crossover. If entered base RPM is higher than this crossover, the lower crossover governs. Verify these illustrative motor ratings against the nameplate.

Gear and equipment values are illustrative engineering defaults and require verification against machine specifications. Gear speed and tension limitations are enforced separately for each selected gear.

Emulsion

Lubrication

Emulsion concentration (%)

Lubricant temperature (°C)

Work roll Ra (µm)

Neat oil viscosity @ 40°C (cSt)

Constant friction µ

Speed-dependent Stribeck-like friction presets remain illustrative and uncalibrated; the solver evaluates different friction at threading and production speed.

Process

Automatic objective: search the minimum feasible number of passes, enforce decreasing percentage reductions, then iteratively approach a front-loaded rolling-force target. Recalculate friction, yield stress, tensions, neutral point and load at every iteration.

Reduction limits

Maximum reduction per pass (%)

Maximum draft per pass (mm)

Minimum reduction per pass (%)

Maximum number of passes

Minimum reduction drop (percentage points / pass)

Target running-force decrease (% of mean / pass)

Tension settings

Initial entry tension (% yield)

Exit/inter-pass tension (% yield)

Speed, coil and timing

Threading speed (m/min)

Coil OD (mm)

Coil ID (mm)

Time per pass overhead (min)

Acceleration (m/s²)

Tension inputs are percentages of local material yield stress. The same intermediate tension (kN) is shared between consecutive passes and automatically limited by the selected gear ratings. There are no separate, redundant stress-cap inputs. A positive reduction-drop setting enforces an earlier-to-later reduction taper; the target force drop is an optimization preference, not permission to exceed hard limits.

Ready

Schedule summary

Pass schedule

Pass	Entry → Exit (mm)	Reduction	Draft (mm)	Gear	Entry T (kN / %YS)	Exit T (kN / %YS)	Thread µ / Force (MN)	Run µ / Force (MN)	Force utilization (worst %)	Neutral / L (%)	Torque / roll (kNm)	Run speed (m/min)	Mill power (kW)	Entry coiler (kW)	Exit coiler (kW)	Time (min)	Limiting condition	Limit / status

Torque uses a provisional equivalent lever arm 0.45 × contact length; contact-length sanity limit L ≤ 0.5R; neutral point and rolling force come from the original v1.4 roll-force numerical solver. Do not use torque and speed estimates as equipment ratings until torque integration and motor-drive calibration are validated.

Rolling force by pass

Threading and running forces must satisfy the derated limit. Optimization targets a gradual decrease in running force toward the final pass, subject to constraints.