Composition
PM S45VN is a high-performance martensitic stainless steel engineered to provide
superior corrosion and wear resistance compared to CPM S35VN. Its rebalanced chemistry results in more chromium carbides while retaining additional free chromium in the matrix. The strategic inclusion of Niobium and Nitrogen instead of some Vanadium and Carbon offers an exceptional blend of edge retention, wear resistance, corrosion resistance, and toughness. This makes it an outstanding choice for EDC knife steel.
The
CPM process ensures a remarkably homogeneous, high-quality steel with unmatched dimensional stability, grindability, and toughness, significantly superior to steels produced through traditional melting practices.
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 applications are typical. Ensure independent study and evaluation for your specific needs.
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)
Despite similar longitudinal toughness of about 25-28 ft. lbs., the transverse toughness of CPM grades is four times higher than that of 440C and 154CM. This higher transverse toughness indicates CPM S45VN, CPM S35VN, and CPM S30V are significantly more resistant to chipping and breaking under lateral stress, making them ideal for larger blades.
Edge Retention(CATRA Testing Relative to 440C)
Testing
The CATRA (Cutlery & Allied Trades Research Association) test machine executes a standardized cutting operation, precisely measuring the number of silica-impregnated cards that are cut. This is recognized as an indicator of relative wear resistance. The results are presented in this table, benchmarked against a 440C standard. *Estimate based on comprehensive market feedback.
Thermal Treatments:
Forging:
2100°F (1150°C). It's crucial to not forge below 1750°F (950°C).
Annealing:
Heat the material to 1650°F (900°C) and hold for 2 hours. Then, cool slowly at a rate no faster than 25°F (15°C) per hour until it reaches 1100°F (595°C). Subsequently, continue to cool in a furnace or still air until room temperature is achieved.
Annealed Hardness: Approximately BHN 255.
Stress Relieving Annealed Parts:
Heat to a temperature range of 1100-1300°F (595-705°C), maintaining it for 2 hours. Then, cool in a furnace or still air. For hardened parts, heat to 25-50°F (15-30°C) below the initial tempering temperature, hold for 2 hours, and then cool in a furnace or still air.
Straightening:
Best performed when warm at temperatures of 400-800°F (200-425°C). Preheat for Hardening: Heat to 1550-1600°F (845-870°C) and equalize.
Austenitize:
Heat to 1900-2000°F (1035-1095°C) and hold for 15-30 minutes. Quenching can be done with air or positive pressure (minimum 2 bar) to below 125°F (50°C), or using a salt or interrupted oil quench to about 1000°F (540°C), followed by air cooling to below 125°F (50°C).
Temper:
Perform a double temper at 400-750°F (200-400°C), holding for a minimum of 2 hours each time. (Refer to table for more details.) A freezing treatment can be applied between the first and second temper to achieve maximum hardenability, and must always be followed by at least one temper.
NOTE: For optimal stress relieving, CPM S45VN may be tempered at 1000-1025°F (540-550°C). Be aware that tempering within this range may slightly reduce corrosion resistance.
Size Change:
+0.05 to +0.10% when fully martensitic. The presence of retained austenite may reduce overall growth. Freezing treatments may be essential to minimize retained austenite during tempering at 400-750°F (200-400°C).
Recommended Heat Treatment:
Austenitize at 1950°F (1065°C). Quench to below 125°F (50°C). Perform a double temper at 600°F (315°C) for a minimum of 2 hours each temper. Ensure the material cools to hand-warm between tempers. Optionally, a freezing treatment can be incorporated between tempers.
Target hardness: 59-61 HRC.
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