C
PM S45VN is a martensitic stainless steel meticulously engineered to offer
enhanced corrosion and wear resistance compared to CPM S35VN. Its chemistry has been expertly rebalanced to form more chromium carbides while maintaining an increased amount of free chromium in the matrix. The substitution of Niobium and Nitrogen for some of the Vanadium and Carbon results in an outstanding combination of edge retention, wear resistance, corrosion resistance, and toughness properties, making it the quintessential choice for an everyday carry (EDC) knife steel.
The
CPM process yields exceptionally homogeneous, high-quality steel distinguished by superior dimensional stability, grindability, and toughness, surpassing steels produced by conventional melting techniques.
Typical Applications:
Long-Wearing Specialty Cutlery, Plastic Injection and Extrusion Feed Screws and Dies, Non-Return Valve Components, Pelletizing Equipment, Wear Components for Food and Chemical Processing. Note: These are typical applications. Conduct independent study and evaluation to ensure suitability for your specific application.
Chemical Composition:
Physical Properties:
Elastic Modulus32 X 10^6 psi
(221 GPa)
Density0.27 lbs./in^3
(7.47 g/cm^3)
Thermal Conductivity
BTU/hr-ft-°F
W/m-°K
cal/cm-s-°C
200°F
93°C
10
17.31
4.13 X 10^-2
Coefficient of Thermal Expansion
°F
°C
in/in/°F
mm/mm/°C
7
0 - 400
(20 - 200)
6.1 X 10^-6
(11.0 X 10^-6)
70 - 600
(20 - 315)
6.4 X 10^-6
(11.5 X 10^-6)
Mechanical Properties:
Toughness(Transverse Charpy C-notch Testing)
While the longitudinal toughness of all four grades is approximately 25-28 ft. lbs., the transverse toughness of the CPM grades is significantly higher—four or more times that of 440C and 154CM. This increased transverse toughness means that CPM S45VN, CPM S35VN, and CPM S30V are far more resistant to chipping and breaking under side loading conditions. In knifemaking, this makes CPM grades particularly suited for larger blades.
Edge Retention(CATRA Testing Relative to 440C)
T
The CATRA (Cutlery & Allied Trades Research Association) test machine conducts a standardized cutting operation, measuring the number of silica-impregnated cards it cuts. This is a widely recognized measure of relative wear resistance, reported here in comparison to a 440C standard. *Estimate based on market feedback
Thermal Treatments:
Forging:
2100°F (1150°C). Do not forge below 1750°F (950°C).
Annealing:
Heat to 1650°F (900°C), hold for 2 hours, then cool slowly at a rate no faster than 25°F (15°C) per hour to 1100°F (595°C). Finally, furnace cool or allow to cool in still air to room temperature.
Annealed Hardness: Approximately BHN 255
Stress Relieving Annealed Parts:
Heat to 1100-1300°F (595-705°C), hold for 2 hours, then furnace cool or allow to cool in still air. For hardened parts, heat to 25-50°F (15-30°C) below the original tempering temperature, hold for 2 hours, then furnace cool or allow to cool in still air.
Straightening:
Best performed at 400-800°F (200-425°C). Hardening Preheat: Heat to 1550-1600°F (845-870°C) and equalize.
Austenitize:
1900-2000°F (1035-1095°C), hold at temperature for 15-30 minutes. Quench: Use air or positive pressure quenching (2 bar minimum) to below 125°F (50°C), or use salt or interrupted oil quenching to approximately 1000°F (540°C), then air cool to below 125°F (50°C).
Temper:
Double temper at 400-750°F (200-400°C), holding for at least 2 hours each time. Refer to the table for detailed information. A freezing treatment between the first and second temper can be applied to achieve maximum hardenability. This treatment must be followed by at least one temper.
NOTE: For optimal stress relief, CPM S45VN can be tempered at 1000-1025°F (540-550°C). Be aware that tempering within this range might slightly reduce corrosion resistance.
Size Change:
+0.05 to +0.10% when fully martensitic. The presence of retained austenite can reduce net growth. To minimize retained austenite, freezing treatments might be necessary when tempering at 400-750°F (200-400°C).
Recommended Heat Treatment:
Austenitize at 1950°F (1065°C). Quench to below 125°F (50°C). Double temper at 600°F (315°C) for a minimum of 2 hours each temper. Cool to hand warmth between tempers. An optional freezing treatment can be added between tempers.
Target hardness: 59-61 HRC.
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