Introduction
Modern rolling mills demand high-performance rolls with excellent wear resistance and extended service life. To meet this challenge, semi-high-speed steel rolls have become a preferred choice due to their superior hardness, toughness, and resistance to thermal fatigue and accidents.
At CYKC GROUP, we have developed a proven forging process to ensure each roll blank meets the strictest quality standards. Since 2002, our team has continuously optimized the production technology of semi-high-speed steel rolls, achieving remarkable results in both quality and performance.
Why Choose Semi-High Speed Steel Rolls?
Semi-high speed steel combines the wear resistance of high-speed steel with improved toughness. It contains carbide-forming elements like Cr, Mo, and W, offering high hardness retention even at elevated temperatures. These characteristics make it ideal for demanding rolling mill applications where roll failure is not an option.
Key Technical Requirements
- Chemical Composition: Optimized for carbide formation and heat resistance.
- Ultrasonic Testing: 100% UT per GB/T13315-91, Grade A.
- Macrostructure: No cracks, white spots, shrinkage, or bubbles allowed.
- Microstructure: Pearlite Grade 1–3; Eutectic Carbides ≤ Grade 2.
Our Advanced Forging Process
To ensure consistent roll quality, we use a strict production route:
Electroslag Remelting (ESR)
We adopt double refining (LF + ESR) to reduce inclusions and gas content, ensuring high-purity steel with minimal segregation.
Heating Protocol
- We follow a multi-stage heating process that includes:
- Slow heating at low temperatures.
- Homogenization above phase transition.
- Holding and controlled cooling.
- Starting forging temperature is maintained at 1130–1150°C to optimize plasticity.
Precision Forging Strategy
- Our success lies in the “Split Forging + Light-Heavy-Light” technique, which includes:
- Initial shaping with light blows to break casting structure.
- Heavy upsetting to crush carbides and improve core structure.
- Final drawing with controlled pressure to avoid inner cracks.
- We also use a combination of one upper flat die and two lower V dies to ensure proper shaping and avoid stress concentration.
Post-Forging Heat Treatment
- The heat treatment curve includes:
- Normalizing: for stress relief.
- Spheroidizing anneal: for carbide refinement.
- Dehydrogenation: to prevent white spot formation.
Results and Benefits
- Two forged roll blanks passed all inspections.
- No internal cracks or structural defects.
- Carbide distribution fully optimized.
- Exceptional wear resistance and surface finish durability.
Why Choose CYKC?
- 20+ years of forging expertise.
- Advanced ESR and forging equipment.
- Custom solutions for every mill type.
- Proven track record with global steelmakers.
Conclusion
Forging semi-high speed steel rolls requires both technical know-how and reliable equipment. At CYKC, we deliver both. Our unique forging strategy ensures roll blanks with superior structure, toughness, and performance.
Contact us today for high-quality roll blanks that keep your rolling mill running longer and more efficiently.
Contact us： cykc@cykcgroup.com.cn