China Carbide Grades Guide: K10, K20, K30, K01 & More

Cemented carbide from China is recognized for its cost-effectiveness, making it a viable option for applications that don’t necessitate the highest performance levels but still require the durability and efficiency of cemented carbide. Known for its exceptional hardness and heat resistance, cemented carbide is a go-to material in industries that demand robust cutting tools.

Composition and Applications of Cemented Carbide

Cemented carbide is a composite material typically formed by sintering a mixture of carbide powders with a binder metal, usually cobalt. At room temperature, these materials exhibit hardness ratings from 86 to 93 HRA, which correlates to 69 to 81 HRC. Their ability to maintain hardness at temperatures as high as 900-1000°C enables significantly higher cutting speeds and tool life compared to high-speed steel.

Due to its hardness and brittleness, cemented carbide is not suited for traditional mechanical processing and is usually manufactured into specific shapes or brazed onto tool bodies.

Classification of Common Cemented Carbide Grades in China

Cemented carbides in China are categorized into different grades based on their composition and mechanical properties:

1. Tungsten-Cobalt (WC-Co) Cemented Carbide

   • Chemical Composition: Primarily tungsten carbide and cobalt.
   • Grade Notation: Denoted by “YG” followed by a number indicating the percentage of cobalt. For instance, YG6 has 6% cobalt.
   • Properties: Higher cobalt content provides better strength and toughness. Lower cobalt content enhances hardness and heat resistance.
   • Color Code: Often marked in red.

2. Tungsten-Cobalt-Titanium (WC-Co-Ti) Cemented Carbide

   • Chemical Composition: Contains tungsten carbide, titanium carbide, and cobalt.
   • Grade Notation: Represented by “YT” followed by a number which signifies the titanium carbide content percentage. For example, YT15 means 15% titanium carbide.
   • Properties: Offers increased hardness and wear resistance. A thin titanium oxide layer forms on the surface during use, reducing chip adhesion and enhancing hot hardness.
   • Color Code: Typically marked in blue.

3. Universal Cemented Carbide

   • Chemical Composition: Similar to YT series but replaces titanium carbide with tantalum carbide (TaC) or niobium carbide (NbC).
   • Grade Notation: Denoted by “YW” followed by a number, which is more about the sequence rather than compositional information.
   • Properties: Combines the advantages of WC-Co and WC-Co-Ti carbides, making it highly versatile.
   • Color Code: Marked in yellow.

Application Suitability

• YG Series: Ideal for machining brittle materials such as cast iron due to its toughness.
• YT Series: Best suited for machining ductile materials like steel, thanks to its hardness and wear resistance.
• YW Series (Universal Carbide): Applicable across a broad range of materials and machining operations due to its balanced properties.

Conclusion

When selecting the appropriate grade of China-made cemented carbide, it is crucial to consider the specific requirements of the application, including the type of material to be machined and the desired machining characteristics such as finish quality and tool life. Each grade offers distinct advantages and is engineered to meet diverse industrial needs effectively.
Related articles:

• Tungsten Carbide Grades (ISO K, M, P): Chart, WC Content & Applications Guide