Cobalt-Free Super High Speed Steel Cpm Rex20/Pm20 Powder Metallurgy HSS Steel

• Type: Special Steel Bar
• Standard: AISI, ASTM, DIN, JIS, GB, BS
• Composition: Stainless Steel Scrap
• Technique: Forged
• Shape: Bar
• Surface Treatment: Polished
• Model NO.: powder high speed steel
• 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

 

CPM Rex 20(AISI M62) is a cobalt-freesuper high speed steel . It has heat treat response and red hardness comparable to that of M42 but offers better wear reisistance and greater toughness. CPMRex 20 was originally designed to replace M42 in any application where cobalt is undesirable. Due to its unique combination of properties, CPM Rex 20 is used in non-cutting applications such as bearings and in plasticizing components such as screw segments, barrels and non-return valves.

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:
EndMills Shaper Cutters Form Tools Broaching Tools Gear Hobs Spade Drills Milling Cutters Special Taps Bearings Plastics Tooling

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

Chemical Composition:

CPM Rex20	Carbon	Chromium	Vanadium	Tungsten	Molybdenum	Cobalt	Sulfur
	1.30%	3.75%	2.00%	6.25%	10.50%	None	0.06 (0.22%)*

         
*Sulfur is added to improve the machinability of larger diameter rounds (e.g. 2-9/16" and over). The higher sulfur content benefits the toolmaker by increasing the ease of manufacture, and benefits the tool user by increasing the ease of resharpening. The CPM process permits the use of sulfur without affecting the tool's performance.

Physical Properties:
Elastic Modulus     34 X106psi      235 GPa
Density            0.295 lbs/in3     8.17 g/cm3
Coefficient of Thermal Expansion

°F              °C             in/in/°F             mm/mm/°C
70-200         20-94           5.92 X 10-6         10.66 X 10-6
70-400         20-205          6.21 X 10-6         11.18 X 10-6
70-600         20-315          6.47 X 10-6         11.65 X 10-6
70-800        20-425           6.60 X 10-6         11.88 X 10-6
70-1000       20-540           6.80 X 10-6         12.24 X 10-6
70-1100       20-595           6.99 X 10-6         12.58 X 10-6

Machinability and Grindability:
Machinability of CPM Rex 20 in the annealed condition is approximately 35% of W1 Tool Steel (1%C).

Grindability of CPM Rex 20 compares favorably with regular high speed steels because of its 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: 1490°F (810°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 262/285

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 tem pering 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 rec ommended to minimize hold time needed at austenitizing temperature.

Austenitize:
2100-2200°F (1150-1205°C) Standard recommendation to achieve HRC 66-68 is 2150 2175°F (1175-1190°C).

Quench:
Quench rapidly to below 1100°F (595°C), equalize, 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. Afast 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 tempering is 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.