CPM 10V Steel: Properties and Key Applications

CPM 10V steel is a high-performance tool steel known for its exceptional wear resistance and toughness. Classified as a high-carbon, high-vanadium alloy steel, CPM 10V is part of the CPM (Crucible Particle Metallurgy) family, which enhances its properties through advanced manufacturing techniques. The primary alloying elements in CPM 10V include carbon (C), vanadium (V), chromium (Cr), and molybdenum (Mo), each contributing to the steel's overall performance.

Comprehensive Overview

CPM 10V is characterized by its high carbon content (around 1.5%) and significant vanadium content (approximately 9.0%), which provide excellent hardness and wear resistance. The chromium and molybdenum enhance its toughness and corrosion resistance, making it suitable for demanding applications. The unique particle metallurgy process used in its production results in a fine, uniform microstructure that further improves its mechanical properties.

Advantages:
- Exceptional Wear Resistance: The high vanadium content contributes to the formation of hard vanadium carbides, which significantly enhance wear resistance.
- High Toughness: Despite its hardness, CPM 10V maintains good toughness, reducing the risk of chipping or cracking during use.
- Good Edge Retention: Ideal for cutting tools and blades, CPM 10V retains a sharp edge longer than many other tool steels.

Limitations:
- Difficult to Machine: The high hardness can make machining and grinding more challenging compared to lower alloy steels.
- Cost: Generally more expensive than conventional tool steels due to the advanced manufacturing process and alloying elements.

Historically, CPM 10V has gained popularity in the manufacturing of high-performance cutting tools, such as knives and industrial blades, due to its superior properties. Its market position is strong among tool steels, particularly for applications requiring high wear resistance and toughness.

Alternative Names, Standards, and Equivalents

Standard Organization	Designation/Grade	Country/Region of Origin	Notes/Remarks
UNS	T10402	USA	Closest equivalent to AISI D2 with higher vanadium content
AISI/SAE	CPM 10V	USA	High-performance tool steel
ASTM	A681	USA	Specification for tool steels
JIS	SKD11	Japan	Similar properties but different composition
ISO	1.2379	International	Equivalent with minor compositional differences

The differences between CPM 10V and its equivalents, such as JIS SKD11, primarily lie in the vanadium content and the manufacturing process, which can affect performance in specific applications.

Key Properties

Chemical Composition

Element (Symbol and Name)	Percentage Range (%)
C (Carbon)	1.50 - 1.60
V (Vanadium)	8.00 - 9.00
Cr (Chromium)	4.00 - 5.00
Mo (Molybdenum)	1.00 - 1.50
Mn (Manganese)	0.20 - 0.50
Si (Silicon)	0.20 - 0.50
P (Phosphorus)	≤ 0.030
S (Sulfur)	≤ 0.030

The primary role of the key alloying elements in CPM 10V is as follows:
- Vanadium (V): Enhances wear resistance through the formation of hard carbides.
- Chromium (Cr): Improves hardness and corrosion resistance.
- Molybdenum (Mo): Increases toughness and helps maintain hardness at elevated temperatures.

Mechanical Properties

Property	Condition/Temper	Test Temperature	Typical Value/Range (Metric)	Typical Value/Range (Imperial)	Reference Standard for Test Method
Tensile Strength	Quenched & Tempered	Room Temp	2100 - 2300 MPa	305 - 335 ksi	ASTM E8
Yield Strength (0.2% offset)	Quenched & Tempered	Room Temp	1800 - 2000 MPa	261 - 290 ksi	ASTM E8
Elongation	Quenched & Tempered	Room Temp	3 - 5%	3 - 5%	ASTM E8
Hardness (HRC)	Quenched & Tempered	Room Temp	58 - 62 HRC	58 - 62 HRC	ASTM E18
Impact Strength (Charpy)	Quenched & Tempered	-20 °C	20 - 30 J	15 - 22 ft-lbf	ASTM E23

The combination of high tensile and yield strength, along with excellent hardness, makes CPM 10V suitable for applications requiring high mechanical loading and structural integrity, such as cutting tools and dies.

Physical Properties

Property	Condition/Temperature	Value (Metric)	Value (Imperial)
Density	Room Temp	7.85 g/cm³	0.284 lb/in³
Melting Point/Range	-	1420 - 1450 °C	2590 - 2640 °F
Thermal Conductivity	Room Temp	25 W/m·K	14.5 BTU·in/h·ft²·°F
Specific Heat Capacity	Room Temp	460 J/kg·K	0.11 BTU/lb·°F
Electrical Resistivity	Room Temp	0.00001 Ω·m	0.00001 Ω·in

The density and melting point of CPM 10V indicate its robustness, while its thermal conductivity and specific heat capacity are crucial for applications involving thermal cycling or heat treatment processes.

Corrosion Resistance

Corrosive Agent	Concentration (%)	Temperature (°C)	Resistance Rating	Notes
Chlorides	3 - 10	20 - 60	Fair	Risk of pitting corrosion
Acids	1 - 5	20 - 40	Poor	Not recommended
Alkaline Solutions	1 - 10	20 - 60	Fair	Susceptible to stress corrosion cracking
Atmospheric	-	-	Good	Performs well in dry conditions

CPM 10V exhibits moderate corrosion resistance, particularly in atmospheric conditions. However, it is susceptible to pitting in chloride environments and should be avoided in acidic or highly alkaline conditions. Compared to other tool steels like D2, which has lower corrosion resistance, CPM 10V performs better in applications where wear resistance is critical, but care must be taken in corrosive environments.

Heat Resistance

Property/Limit	Temperature (°C)	Temperature (°F)	Remarks
Max Continuous Service Temp	400 °C	752 °F	Suitable for high-temperature applications
Max Intermittent Service Temp	500 °C	932 °F	Short-term exposure only
Scaling Temperature	600 °C	1112 °F	Risk of oxidation beyond this point
Creep Strength considerations	400 °C	752 °F	Creep resistance begins to decline

At elevated temperatures, CPM 10V maintains its hardness and wear resistance, but oxidation can become a concern if not properly protected. The steel's performance in high-temperature applications is generally good, making it suitable for hot work tooling.

Fabrication Properties

Weldability

Welding Process	Recommended Filler Metal (AWS Classification)	Typical Shielding Gas/Flux	Notes
TIG	ER80S-D2	Argon	Preheat recommended
MIG	ER80S-D2	Argon + CO2 mix	Requires post-weld heat treatment
Stick	E7018	-	Not recommended for thick sections

Welding CPM 10V can be challenging due to its high hardness. Preheating is often recommended to reduce the risk of cracking, and post-weld heat treatment is essential to restore toughness.

Machinability

Machining Parameter	CPM 10V	AISI 1212	Notes/Tips
Relative Machinability Index	50	100	More difficult to machine
Typical Cutting Speed (m/min)	15 - 25	40 - 60	Use carbide tools for best results

Machining CPM 10V requires specialized tools and techniques due to its hardness. Carbide tooling is recommended, and slower cutting speeds may be necessary to achieve optimal results.

Formability

CPM 10V is not particularly suited for forming operations due to its high hardness and brittleness. Cold forming is generally not recommended, while hot forming may be possible with careful control of temperature and strain rates.

Heat Treatment

Treatment Process	Temperature Range (°C)	Typical Soaking Time	Cooling Method	Primary Purpose / Expected Result
Annealing	800 - 850	1 - 2 hours	Air	Reduce hardness, improve machinability
Hardening	1000 - 1100	30 - 60 minutes	Oil/Water	Achieve maximum hardness
Tempering	500 - 600	1 hour	Air	Reduce brittleness, enhance toughness

The heat treatment process significantly affects the microstructure of CPM 10V, transforming it into a martensitic structure that provides its characteristic hardness and wear resistance. Proper heat treatment is crucial for achieving the desired balance of hardness and toughness.

Typical Applications and End Uses

Industry/Sector	Specific Application Example	Key Steel Properties Utilized in this Application	Reason for Selection
Tool Manufacturing	Cutting Tools	High wear resistance, toughness	Long-lasting edge retention
Aerospace	Aircraft Components	High strength-to-weight ratio	Durability under stress
Automotive	Engine Components	High-temperature performance	Reliability in harsh conditions
Medical Devices	Surgical Instruments	Corrosion resistance, sharpness	Precision and safety

Other applications include:
* Knives and blades for industrial use
* Dies and molds for metal forming
* High-performance wear parts in machinery

CPM 10V is chosen for these applications due to its unique combination of hardness, wear resistance, and toughness, making it ideal for tools that require prolonged use under demanding conditions.

Important Considerations, Selection Criteria, and Further Insights

Feature/Property	CPM 10V	AISI D2	M2 Tool Steel	Brief Pro/Con or Trade-off Note
Key Mechanical Property	High hardness	Good wear resistance	High toughness	CPM 10V offers superior wear resistance
Key Corrosion Aspect	Moderate	Fair	Poor	CPM 10V performs better in corrosive environments
Weldability	Challenging	Moderate	Good	Requires preheat and post-weld treatment
Machinability	Difficult	Moderate	Good	CPM 10V is harder to machine than D2
Formability	Poor	Fair	Good	Limited forming capability
Approx. Relative Cost	High	Moderate	Moderate	Higher cost due to advanced processing
Typical Availability	Moderate	High	High	CPM 10V may be less readily available

When selecting CPM 10V, considerations include its cost-effectiveness for specific applications, availability in the market, and the need for specialized machining and welding techniques. Its unique properties make it suitable for niche applications where performance is critical, despite the challenges in fabrication and higher costs compared to other tool steels.

In summary, CPM 10V steel is a high-performance tool steel that excels in wear resistance and toughness, making it ideal for demanding applications in various industries. Its advanced properties, however, come with challenges in machining and welding, necessitating careful consideration during the selection process.