Withdrawal & Straightening Category Overview
The Withdrawal & Straightening Machine is a critical downstream unit in the continuous casting process, responsible for extracting the semi‑solidified strand from the mold and correcting its curvature before final cutting or downstream rolling. Haijie Machinery’s Withdrawal & Straightening line combines robust mechanical design, precise tension control, and intelligent automation to deliver consistent strand geometry, minimize shell defects, and ensure seamless integration with cutting, coiling, or rolling systems.
The Withdrawal & Straightening Machine consists of a series of driven and idle roller stands arranged over a segmented frame. As the strand exits the mold, synchronized traction rollers grip and pull the strand at controlled speeds, while the straightening segment applies corrective forces to eliminate residual bow and camber. The assembly is engineered to handle billet and bloom sections from 80 × 80 mm up to 160 × 160 mm, with pull forces up to 250 kN per stand.
Synchronized Traction Rolls
Multiple servo‑driven pullers with closed‑loop speed control maintain constant strand velocity within ±0.5 % tolerance.
High‑friction composite sleeves optimize grip and reduce slippage, even at elevated temperatures.
Multi‑Stage Straightening Banks
Three consecutive roller zones (pre‑straightening, primary straightening, final correction) allow fine‑tuning of residual curvature.
Hydraulic gap adjustment in each zone adapts to varying billet sizes and shell stiffness.
Intelligent Control System
PLC and HMI integration provides real‑time tension, speed, and straightness feedback.
Auto‑tension mode adjusts puller torque based on inline laser gap measurements, ensuring consistent straightness without manual intervention.
Heavy‑Duty Frame & Bearings
Welded steel frame with rib‑reinforced girders withstands dynamic loads and thermal expansion.
High‑temperature sealed bearings in idle stands eliminate maintenance-intensive lubrication.
Integrated Cooling & Lubrication
Roller stands incorporate internal water jackets to dissipate heat from hot shells.
Centralized automatic lubrication system extends roller sleeve and bearing life.
Superior Strand Quality
Reduces camber and bow to less than 1 mm/m, ensuring optimal downstream processing and minimizing scrap.
High Throughput
Capable of speeds up to 6 m/min for bloom and 4 m/min for billet lines, matching modern casting rates.
Low Maintenance
Modular puller and straightener units allow rapid replacement of wear parts without full line shutdown.
Energy Efficiency
Regenerative drives capture braking energy, reducing overall power consumption by up to 7 %.
Operator Safety & Ergonomics
Guarded enclosures, light‑curtain safety sensors, and remote diagnostics protect personnel and equipment.
Carbon Steel Billet Casting
Ensures straight, defect‑free billets for automotive, construction, and machinery uses.
Alloy and Stainless Steel Blooms
Handles higher temperature ranges and softer shell conditions without slippage.
Long Product Casting
Integration with beam blank caster lines for H‑beam, I‑beam, and rail steel production.
Continuous Bloom to Bar Rolling
Serves as the link between CCM and roughing stands in bar and rod mills.
Variable Puller Configurations
Dual‑tandem or triple‑tandem pullers for enhanced traction on larger cross‑sections.
Laser Straightness Measuring
Inline laser scanners for non‑contact, high‑precision curvature mapping.
Extended Frame Length
Customized frame modules to fit non‑standard plant layouts or additional cooling zones.
Remote Monitoring Package
IoT‑enabled sensors streaming tension, temperature, and vibration data to cloud analytics for predictive maintenance.
What billet sizes can the Withdrawal & Straightening Machine handle?
Standard models cover 80 × 80 mm up to 160 × 160 mm; custom sizing up to 200 × 200 mm is available.
How is strand tension controlled during withdrawal?
Servo‑driven pullers operate in closed‑loop with inline speed and torque feedback; optional load cells measure actual traction force.
What is the typical straightening accuracy?
Residual curvature is controlled to within 1 mm per meter of strand length under auto‑tension mode.
How do you manage roller wear and replacement?
Composite roller sleeves are replaceable in under 2 hours per stand; automatic lubrication further extends sleeve life to over 5,000 hours.
Is operator training and commissioning support offered?
Yes. Haijie provides full FAT/SAT, on‑site mechanical and electrical commissioning, plus three days of dedicated operator and maintenance training.
By integrating Haijie’s Withdrawal & Straightening solutions, steel mills achieve consistent strand geometry, higher yield, and streamlined downstream operations—supported by our proven engineering expertise and commitment to quality.
