Pm76/Cpm Rex76 Material HSS Black Surface Forging Steel Hot Rolled Steel Flat Bar Round Bar

• Type: Special Steel Bar
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Bar
• Surface Treatment: Polished
• Special Use: High-strength Steel Plate, Wear Resistant Steel, Silicon Steel, Cold Heading Steel, Free Cutting Steel, Mold Steel
• Application: Die Steel Bar
• Length: 2500-5500mm
• Material: HSS
• Usage: Gear Hob
• Customized Support: OEM
• Transport Package: N/M
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7226911000
• Production Capacity: 1000ton/Month

Product Description

Detailed Photos

Product Description

 

PM76/CPM Rex 76 is a super high speed steel made by the CPM (Crucible Particle Metallurgy) Process. It is heat treatable to HRC 68-70. Itshigh carbon,vanadium and cobalt contents provide abrasion resistance comparable to that of T15 and red hardness superior to that of M42. With its high hardness, fine grain size and uniform car bide distribution, CPM Rex 76 is an outstanding choice for special purpose cutting tools requiring high red hard ness, high abrasion resistance, and good toughness.

The CPM process results in a homogeneous microstructure with a finer, more uniform carbide distribution imparting superior dimensional stability, grindability and toughness when compared to steels produced by conventional processes. The CPM process also allows the design of more highly alloyed grades which cannot be produced by conventional steelmaking.

Typical Applications:
End Mills
Form Tools
Shaper Cutters
Gear Hobs
Broaches
Spade Drills
Tool Bits
Milling Cutters
Special Taps

Note: These are some typical applications. Your specific application should not be undertaken without independent study and evaluation for suitability.


Chemical Composition:

CPM Rex76	Carbon	Chromium	Vanadium	Tungsten	Molybdenum	Cobalt	Sulfur
	1.50%	3.75%	3.10%	9.75%	5.25%	8.50%	0.07 (0.22%)*

        



Physical Properties:
Elastic Modulus     31 X106psi         214 GPa
Specific Gravity    8.26
Density             0.298 lbs/in3      8.255 g/cm3

Coefficient of Thermal Expansion

°F             °C             in/in/°F        mm/mm/°C
70-200         20-95          5.92 X 10-6    10.66 X 10-6
70-400         20-200         6.00 X 10-6    10.80 X 10-6
70-600         20-315         6.15 X 10-6    11.07 X 10-6
70-800         20-425         6.33 X 10-6    11.39 X 10-6
70-1000        20-540         6.52 X 10-6    11.74 X 10-6
70-1200        20-650         6.75 X 10-6    12.15 X 10-6


Machinability and Grindability:
Machinability in the annealed condition is approximately 15% of W1 Tool Steel (1%C). Grindabilityof CPM Rex 76 compares favorably with regular high speed steels because of the fine, uniformly distributed carbides. Conventional grinding wheels designed for high speed steels can be used. In special cases, the advice of a grinding wheel manufacturer should be sought.

Thermal Treatments:
Critical Temperature: 
1535°F (835°C) Forging: 2000-2100°F (1095-1150°C). Do not forge below 1700°F (925°C). Slow cool after forging.

Annealing
Heat to 1600°F (870°C), hold 2 hours, slow cool no faster than 25°F (15°C) per hour to 1000°F (540°C), then furnace cool or cool in still air to room temperature.
Annealed Hardness: Approx. BHN 285/311 

Stress Relieving Annealed parts: 
Heat to 1100-1300°F (595-705°C), hold 2 hours, then furnace cool or cool in still air.
Hardened parts: 
Heat to 25°F (15°C) below original tempering temperature, or 1000°F (540°C) minimum, hold 2 hours, then furnace cool or cool in still air.

Hardening (Salt or High Pressure Vacuum preferred)
Pre-heat:
Heat to 1500-1550°F (815-845°C), hold long enough to soak through. For vacuum heat treating, an additional pre-heat at 1850-1900°F (1010-1040°C) is recommended to minimize hold time needed at austenitizing temperature.

Austenitize:
2100-2190°F (1150-1200°C) Standard recommendation to achieve HRC 67-69 is 2150 2175°F (1175-1190°C).

Quench: 
Quench rapidly to below 1100°F (595°C), equal ize, then air cool to hand warm, below 125°F (50°C). Salt or interrupted oil quenching usually gives the best heat treat response for high speed steels. A fast quench rate from hardening temperature to below 1100°F (595°C) is critical to achieve optimum heat treat response.

Temper: 
1000°F (540°C) minimum. Triple or quadruple tempering required, hold 2 hr. minimum at temperature. Cool to room temperature between tempers.

Straightening:
Best done warm 400°F minimum (205°C). Straightening after salt quenching and before cooling to below 400°F (205°C) is preferred.