C
PM S45VN is a martensitic stainless steel meticulously engineered to provide
superior corrosion and wear resistance relative to CPM S35VN. The rebalanced chemistry significantly enhances the formation of chromium carbides while simultaneously increasing the free chromium content in the matrix. The strategic incorporation of Niobium and Nitrogen, replacing some Vanadium and Carbon, culminates in an extraordinary blend of edge retention, wear resistance, corrosion protection, and toughness. This makes PM S45VN the quintessential choice for EDC knife steel.
The
CPM process guarantees exceptionally homogeneous, high-quality steel, offering unparalleled dimensional stability, grindability, and toughness compared to conventional melting methods.
Typical Applications:
Long-Wearing Specialty Cutlery, Plastic Injection and Extrusion Feed Screws and Dies, Non-Return Valve Components, Pelletizing Equipment, and Wear Components for Food and Chemical Processing. Note: These applications are typical uses; a thorough independent study and suitability evaluation is recommended for your specific application.
Chemical Composition:
Physical Properties:
Elastic Modulus32 X 106 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 10-2
Coefficient of Thermal Expansion
°F
°C
in/in/°F
mm/mm/°C
7
0 - 400
(20 - 200)
6.1 X10-6
(11.0 X10-6)
70 - 600
(20 - 315)
6.4 X10-6
(11.5 X10-6)
Mechanical Properties:
Toughness(Transverse Charpy C-notch Testing)
While the longitudinal toughness of these grades registers around 25-28 ft. lbs., CPM grades exhibit superior transverse toughness—four or more times that of 440C and 154CM. This remarkable transverse toughness signifies CPM S45VN, CPM S35VN, and CPM S30V are exceedingly resistant to chipping and breakage in applications prone to side loading. In knife making, this increased transverse toughness is particularly beneficial for larger blades.
Edge Retention(CATRA Testing Relative to 440C)
T
The venerable CATRA (Cutlery & Allied Trades Research Association) test machine performs a standardized cutting operation to measure the number of silica-impregnated cards cut. This test is recognized industry-wide as a key indicator of relative wear resistance. The results are documented in this table, benchmarked against a 440C standard. *Estimate derived from comprehensive market feedback.
Thermal Treatments:
Forging:
2100°F (1150°C). Ensure not to forge below 1750°F (950°C) to maintain structural integrity.
Annealing:
Heat to a precise 1650°F (900°C), maintain for 2 hours, followed by a controlled slow cooling process not exceeding 25°F (15°C) per hour down to 1100°F (595°C). Finish by furnace cooling or cooling in still air to room temperature.
Annealed Hardness: Approximately BHN 255.
Stress Relieving Annealed Parts:
Heat to 1100-1300°F (595-705°C), sustain for 2 hours, then initiate furnace cooling or still air cooling. For Hardened Parts: Heat to 25-50°F (15-30°C) below the original tempering temperature, hold for 2 hours, then proceed to furnace or still air cooling.
Straightening:
Optimal results are achieved when performed warm at 400-800°F (200-425°C).
Hardening Preheat: Heat to 1550-1600°F (845-870°C) and allow it to equalize.
Austenitize: Reach 1900-2000°F (1035-1095°C) with a hold time of 15-30 minutes. Quench: Employ air or positive pressure quenching (minimum 2 bar) to drop below 125°F (50°C), or utilize a salt or interrupted oil quench to approximately 1000°F (540°C), followed by air cooling to below 125°F (50°C).
Temper:
Execute a double temper at 400-750°F (200-400°C). Maintain for a minimum of 2 hours each cycle. (Refer to Table) Optionally, a freezing treatment can be applied between the first and second tempers to achieve peak hardenability, ensuring it is followed by at least one temper.
NOTE: For optimal stress relief, CPM S45VN may be tempered at 1000-1025°F (540-550°C). Be aware that tempering within this range may lead to a minor reduction in corrosion resistance.
Size Change:
Expect a growth of +0.05 to +0.10% when the material is fully martensitic. The presence of retained austenite could lessen the net growth. When tempering at 400-750°F (200-400°C), freezing treatments might be needed to minimize retained austenite.
Recommended Heat Treatment:
Austenitize at 1950°F (1065°C). Quench to below 125°F (50°C). Execute a double temper at 600°F (315°C) for a minimum of 2 hours per temper. Ensure cooling to hand warm between tempers. Optionally, incorporate a freezing treatment between tempers for enhanced results.
Target Hardness: Aim for a hardness range of 59-61 HRC.
Audited Supplier 
){kind=link}