Durable Carbon Steel Round Bar for Industrial Use

• 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
• Transport Package: N/M
• Specification: 6-400mm
• Trademark: Smooth
• Origin: China
• HS Code: 7226911000
• Production Capacity: 1000ton/Month

Product Description

PM M4Elevate your work with high-speed tool steel, a versatile material renowned for its exceptional blend of high wear-resistance, impact toughness, and bend strength. This excellence is achieved through its fine grain size, minimal carbides, and unparalleled cleanliness. PM M4Experience extended cutting tool longevity with our high-speed tool steel, outperforming conventionally-wrought M1.M2, M7and other lower-alloyed high-speed steels. Our PM M4 stands out in cold work tooling applications, offering superior durability over high-carbon, high-chromium die steels such as D2 and D3.

Other Known Names:CPM REX M4 steel^®, ASP 2004, S690

Common Usage

Ideal for Broaches, End Mills, Punches, Hobs, Fine Blanking, and Forming Dies.

Physical Properties

Density

0.286 lb/in³ (7806 kg/m³)

Specific Gravity

7.92

Modulus Of Elasticity

31 x 10⁶ psi (214 GPa)

Machinability

Achieves 40-45% of the machinability of 1% carbon steel.

PM M4 High Speed Steel Chemical Composition

						MAXIMUM	TYPICAL
Carbon	Chromium	Tungsten	Molybdenum	Vanadium	Cobalt	Annealed	Tempered
C	Cr	W	Mo	V	Co	Hb	HrC
1.4	4	5.65	5.2	4	-	255	65

 

PM M4 High Speed Steel Heat Treating

ANNEALING	PREHEAT	AUSTENITIZING	QUENCH	TEMPERING
Temp	Temp	Temp	Medium	Temp
°F	°F	°F		°F
1550/1600	1500/1550	2175/2220	Salt/Oil/Atm	1025/1050

 

PM M4 High Speed Steel Thermal Treatments

Preheating:
Heat gradually not exceeding 400°F per hour (222°C per hour) to 1500-1600°F (816-871°C), and equalize.

Austenizing (High Heat):

Rapid heating from preheat is essential.

For Cutting Tools:

• Soak for 5 to 15 minutes.
• Furnace: 2150-2175°F (1177-1191°C)
• Salt Bath: 2125-2175°F (1163-1191°C)

For Cold Work Tooling:

• Soak for 20 to 45 minutes.
• Furnace: 1875-2125°F (1023-1163°C)
• Salt Bath: 1850-2100°F (1010-1149°C)

To optimize toughness, use the lowest temperature. For maximum hot hardness, apply the highest temperature.
Quenching:
Use pressurized gas, warm oil, or salt.

For pressurized gas quenching, ensure a furnace with at least 4 bars of pressure. A quench rate of approximately 400°F (222°C) per minute to below 1000°F (538°C) is crucial to achieve the desired properties.

For optimal oil quenching, heat the material until it reaches a deep black, approximately 900°F (482°C). Allow it to cool in still air until it reaches a temperature range of 150-125°F (66-51°C).

When using a salt bath, maintain a consistent temperature between 1000-1100°F (538-593°C). Equalize the material in the salt, then let it cool in still air to 150-125°F (66-51°C).

Tempering:

Proceed with tempering immediately after quenching to ensure material stability.
The standard tempering temperature range is 1000-1100°F (538-593°C). Avoid tempering below 1000°F (538°C). Hold the material at the desired temperature for 2 hours before allowing it to air cool to ambient temperature. Double tempering is essential, and if the material was austenitized at 2100°F (1149°C) or higher, triple tempering becomes necessary.

Annealing:

Annealing is a crucial step that must be carried out after hot working and before re-hardening to ensure the material's optimal properties.

Heat the material at a controlled rate not exceeding 400°F per hour (222°C per hour) until it reaches a temperature of 1550-1600°F (843-871°C). Hold it at this temperature for 1 hour per inch (25.4 mm) of thickness, with a minimum of 2 hours. Allow it to cool slowly within the furnace at a rate not exceeding 50°F per hour (15°C per hour) down to 1000°F (538°C). Finally, continue cooling to ambient temperature, either within the furnace or in open air.