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What is CPM 15V Steel?
CPM 15V steel is a high carbon, high vanadium tool steel produced by Crucible industries following Crucible Particle Metallurgy. CPM 15V contains more Vanadium than its predecessor CPM 10V, and has one of the highest amounts of Vanadium (14.50%) of all CPM tool steels.
CPM 15V is made for applications that require exceptional wear resistance. It has solid carbides that can withstand high wear resistance application. 15V steel is used to make punches, core rods, Barrel liners, wear inserts, forming, cold extrusion, piercing, and industrial knives.
Several custom knife makers use CPM 15V blade steel due to its incredible wear resistance and extremely high edge retention. 15V knife steel edge retention is in the range of other hard steels like Z-Max Steel and S125V steel.
CPM 15V Steel Composition
- Carbon C 3.40%: Increases edge retention, hardness, and tensile strength. It also improves steel resistance to wear, abrasion, and corrosion.
- Chromium Cr 5.25%: Formation of Chromium carbide Increases the hardness, tensile strength, and corrosion resistance of the blade.
- Molybdenum Mo 1.30%: It improves machinability and hardness.
- Vanadium V 14.50%: Increase wear resistance and toughness, it also improves corrosion resistance.
Properties of CPM 15V steel
CPM 15V Steel Hardness
CPM 15V has a Rockwell hardness of 62 HRC, but the hardness differs with the heat treatment used, and with a good heat treatment technique, it can get to 65 HRC. The high Rockwell hardness is associated with the high amounts of Vanadium Carbide.
15V steel can be hardened at a higher temperature, thus giving it a high hot hardness ensuring the steel remains hard even when operating at high temperatures. This feature makes it appealing for high abrasive applications where temperatures may go up.
CPM 15V Steel Toughness
The toughness of steel is often inversely proportional to the hardness. This means that steels with high hardness offer low toughness, which is true with 15V. On a scale of 1 to 10, 15V knife steel has a toughness of 3, which is very low and comparable to other low toughness steels like S110V.
Because of the low toughness, tools, and knives made from CPM 15V easily fracture and break when exposed to high impact. If you want knives to be used in very challenging applications, opt for knives made from steel with higher toughness than 15V.
CPM 15V Steel Wear Resistance
CPM 15V offers excellent wear resistance because it contains very high amounts of Vanadium forming Vanadium carbides. CPM 15V features a fine microstructure, making it highly resistant to wear and abrasion. Its wear resistance is among the properties that make 15V stand out in the market.
Because of its outstanding wear resistance, 15V makes an excellent choice to make machinery parts prone to wear due to constant exposure to high temperatures. Additionally, it is used to make high-quality and long-lasting knives. Therefore, try the varieties of CPM 15V knives if you want knives to be used for tough applications.
CPM 15V Steel Edge Retention
With a high hardness of up to 65 HRC and excellent wear resistance, CPM 15V knives are outstanding in edge retention. Blades made from this steel do not require regular sharpening; they offer the best edge retention in knife steels.
15V blade steel is better than most knife steel, including S90V steel, 10V, and M398 steels. The only few blade steel offering better edge retention than CPM 15V blade steels are Maxamet and Rex 121 steel.
CPM 15V Steel Corrosion resistance
A big downside of CPM 15V steel is its poor corrosion resistance. It is not stainless steel because it does not contain the required amount of chromium to make it steel stainless. Its corrosion resistance is similar to most high alloy tool steels like 10V, M4, and Vanadis 8.
15V knives easily rust, thus unsuitable for highly corrosive environments. If you are on the market for blades to be used in wet, humid, and areas of salty water, stay away from CPM 15V steel knives and look for S110V steel knives. S110V offers an almost similar level of edge retention as 15V.
However, if you cannot resist the edge retention and wear resistance properties of CPM 15V knives, you can still buy them and fight corrosion through proper care and maintenance. Proper care entails washing and drying the knives immediately after use and applying a coat of oil for storage.
Sharpening CPM 15V Steel
Sharpening CPM 15V blades is not easy, and this is due to its excellent wear resistance brought about by the hard Vanadium carbides. To get a sharp edge, you will need an abrasive diamond that is harder than the Vanadium Carbides.
Despite being powder metallurgy steel with a relatively fine carbide structure, CPM 15V blade steels maintain high wear resistance; hence any form of metal removal like sharpening, grinding, and polishing remains extremely difficult.
CPM 15V Steel Equivalent
Z-Max steel can be considered CPM 15V steel Equivalent In terms of performance aspects like toughness, edge retention, and corrosion resistance. Their chemical compositions are different but match each other in most aspects. Z-Max offers slightly higher toughness.
CPM 15V vs CPM 10V
CPM 15V steel and CPM 10V steel are both products of the Crucible industries. They are not stainless steel and offer the same level of corrosion resistance. However, CPM 15 steel offers better wear resistance and edge retention than 10V steel due to the additional Vanadium elements in its alloy composition.
CPM 10V steel is much more affordable than 15V and is popular with some knife makers due to its high edge retention and average toughness. The toughness of 10V is better than some common tool steels like the D2 steel, while its edge retention is at par with ZDP 189 and better than Rex 45 steel.
Is CPM 15V good knife steel?
CPM 15V is good knife steel because of its high hardness, excellent wear resistance, and outstanding edge retention. However, it offers poor toughness and corrosion resistance; therefore not suitable for outdoor knives.
CPM 15V steel is not commonly adopted in most knives as it is very expensive. The CPM 15V steel production process is extremely complex, and its high wear resistance makes grinding and polishing difficult for mass adoption.