In modern steel mills, the material of the rolls directly affects the rolling efficiency, yield rate, and downtime cost. Hard alloys, with their extremely high hardness, wear resistance, and long service life, have become important materials for high-speed wire rod and bar rolling mills. To obtain high-quality hard alloy rolls, advanced forming processes are crucial. This article will analyze the main forming technologies of hard alloys (WC-Co) and how these technologies improve the performance of the rolls, helping steel mills reduce usage costs and enhance stability.
Why does the forming technology determine the performance of hard alloy rolls?
WC-Co hard alloys are composed of ultra-fine tungsten carbide particles and cobalt binders. The forming stage is the key to determining whether the structure is uniform, the density is sufficient, and the performance is stable.
High density = high hardness + high wear resistance + no chipping + long service life
Whether the rolls you use can roll stably, whether they are prone to chipping, and whether they are wear-resistant all fundamentally depend on the forming quality.
CYKC adopts multiple advanced forming processes to ensure that the rolls have stable and reliable performance.
Several advanced hard alloy forming processes
Powder extrusion molding (PEM) – The mainstream process for hard alloy round bars
Powder extrusion molding (PEM) involves mixing the powder with the binder and extruding it into a long bar-shaped blank.
Advantages:
- The length of the blank is not limited
- The density is uniform along the longitudinal direction
- Continuous forming and high efficiency
- Suitable for long hard alloy bars, such as roll cores and round bars
Many hard alloy roll cores and round bar blanks are produced using this process, making it one of the most widely used technologies.
Powder injection molding (PIM) – Suitable for complex-shaped parts
Powder injection molding is like a “metal version of plastic injection molding”.
Advantages:
Can manufacture complex-shaped parts.
High surface finish.
Precise product dimensions.
Uniform density.
Suitable for complex hard alloy accessories, but mainly used for special parts (such as wear-resistant sleeves and complex-structured core parts) in the roll field.
Cold isostatic pressing (CIP) – Improving density and structural uniformity
The powder is subjected to uniform pressure from all directions in a liquid medium to form a uniform and dense blank.
Advantages:
Highly uniform density.
Low shrinkage rate.
Higher density and hardness after sintering.
Stable product strength.
Suitable for rolls with high density requirements, such as roll rings and thick-walled hard alloy parts.
Explosive forming (EF) – A new technology for extremely high density
It utilizes the huge instantaneous pressure generated by an explosion for forming.
Characteristics:
The pressure can reach up to 10 MPa, which is difficult to achieve in the long term.
Can achieve a relative density of over 99%.
Significant improvement in material strength and hardness.
This technology is mainly used in the field of ultra-high-performance hard alloys and is one of the trends for high-end rolls in the future.
High-speed pressing (HVC) – Superior performance and suitable for large-sized parts
High-speed pressing uses a heavy hammer to impact the powder at high speed to achieve high-density forming in an extremely short time.
Advantages:
The pressing speed is 500 to 1000 times faster than traditional pressing
More uniform product density
Large-sized hard alloy parts can be pressed
Better mechanical properties
Suitable for large hard alloy rolls, integral annular rolls, etc.
Warm Pressing (PM) – A New Trend for High-strength Billets
Powder is heated to 100–150℃ and pressed in a hot mold.
Advantages:
Significantly increase density
Enhance strength
Helps to manufacture complex structural parts
Warm Flow Compaction (WFC) can produce more complex shapes
Suitable for high-precision hard alloy parts.
The Practical Value of Advanced Forming Processes for Steel Mills
Regardless of the method used, the goal of hard alloy rolls is the same:
Longer life, fewer shutdowns
High density means higher wear resistance and lower probability of spalling.
Stable surface, no chipping or edge cracking
Advanced forming processes can reduce structural defects and make the rolls work more stably.
High precision, high yield
Uniform microstructure can maintain the stability of roll dimensions and reduce the frequency of roll changes.
Suitable for high-speed rolling lines, improving production efficiency
The combination of high hardness and high strength makes hard alloy rolls the preferred choice for high-speed wire and bar production lines.
Advantages of CYKC Hard Alloy Rolls
The hard alloy rolls we supply are made using various advanced powder forming technologies, and the best process is selected based on the customer’s equipment and product requirements.
Our advantages:
Strict selection of raw materials, using high-purity WC+Co powder.
Adopting processes such as CIP, HVC, and PEM ensures uniform microstructure.
The latest formula offers high hardness and excellent toughness.
Suitable for high-speed wire rod and bar rolling mills and high-stress conditions.
The service life is 3 to 10 times longer than that of ordinary alloy rolls.
Our professional technical team provides application suggestions and on-site support.
We not only sell products but also offer solutions to help steel mills reduce roll costs and improve rolling stability.
Conclusion
The performance of cemented carbide rolls is 70% dependent on the forming technology. With the continuous upgrading of powder metallurgy technology, cemented carbide will continue to be a key material for steel mills to improve efficiency, reduce downtime and lower overall costs. It is hoped that this article can help you better understand cemented carbide and its forming technology, and provide a reference for choosing rolls that are more suitable for your production line.