C
PM S45VN is a martensitic stainless steel designed to offer unparalleled
corrosion and wear resistance improvements over CPM S35VN. The rebalanced chemistry of this steel forms more chromium carbides and concurrently retains more free chromium within the matrix. By substituting Niobium and Nitrogen for some of the Vanadium and Carbon, it achieves a remarkable synergy of edge retention, wear resistance, corrosion resistance, and toughness. This makes it the premier choice for an EDC knife steel.
The
CPM process ensures exceptionally homogeneous, top-tier steel characterized by superior dimensional stability, grindability, and toughness—far surpassing steels produced via conventional melting methods.
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 typical applications are provided as general guidelines. Thorough, independent evaluation for specific suitability is recommended.
Chemical Composition
Physical Properties :
Elastic Modulus32 X 10 psi
(221 GPa)
Density0.27 lbs./in³
(7.47 g/cm³)
Thermal Conductivity
BTU/hr-ft-°F
W/m-°K
cal/cm-s-°C
200°F
93°C
10
17.31
4.13 X 10²
Coefficient of Thermal Expansion
°F
°C
in/in/°F
mm/mm/°C
7
0 - 400
(20 - 200)
6.1 X10
(11.0 X10)
70 - 600
(20 - 315)
6.4 X10
(11.5 X10)
Mechanical Properties :
Toughness(Transverse Charpy C-notch Testing)
The longitudinal toughness of all four grades is approximately 25-28 ft. lbs. However, the transverse toughness of CPM grades is significantly higher—four or more times that of 440C and 154CM. This superior transverse toughness indicates that CPM S45VN, CPM S35VN, and CPM S30V better resist chipping and breaking under side loading stresses. For knifemaking, this makes CPM steels ideal for larger blades.
Edge Retention(CATRA Testing Relative to 440C)
T
The CATRA (Cutlery & Allied Trades Research Association) test machine executes a standardized cutting operation to measure the quantity of silica-impregnated cards cut. This serves as an indicator of relative wear resistance, presented here in comparison to a 440C standard. *Estimate based on market feedback.
Thermal Treatments:
Forging:
Forge at 2100°F (1150°C). Ensure not to forge below 1750°F (950°C).
Annealing:
Heat to 1650°F (900°C), hold for 2 hours. Cool slowly at a rate no faster than 25°F (15°C) per hour to 1100°F (595°C), then allow to furnace cool or in still air to room temperature.
Annealed Hardness: Approximately BHN 255.
Stress Relieving Annealed Parts:
Heat to 1100-1300°F (595-705°C) and hold for 2 hours. Allow to furnace cool or in still air. For hardened parts, heat to 25-50°F (15-30°C) below the original tempering temperature, hold for 2 hours, then allow to furnace cool or in still air.
Straightening:
Best performed warm at 400-800°F (200-425°C) Hardening Preheat: Heat to 1550-1600°F (845-870°C) and equalize.
Austenitize:
Heat to 1900-2000°F (1035-1095°C) and hold at temperature for 15-30 minutes. Quench using air or positive pressure (minimum 2 bar) until below 125°F (50°C), or use salt or interrupted oil quench to about 1000°F (540°C), then allow to 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 Table for specifics.) A freezing treatment can be applied between the first and second temper to achieve maximum hardenability, which must be followed by at least one temper.
NOTE: For optimal stress relief, temper CPM S45VN at 1000-1025°F (540-550°C). It’s worth noting that tempering in this range may slightly decrease corrosion resistance.
Size Change:
Expect a size change of +0.05 to +0.10% when fully martensitic. The presence of retained austenite could reduce net growth. When tempering at 400-750°F (200-400°C), freezing treatments may be required to minimize retained austenite.
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 per temper. Allow to cool to hand warm between tempers. A freezing treatment may be applied between tempers.
Target hardness: Aim for 59-61 HRC.
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