High Speed Tool Steel Bar Smooth 6-400mm

• 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 M4Our high speed tool steel is a highly versatile material known for its exceptional blend of high wear-resistance, remarkable impact toughness, and superior bending strength. This outstanding performance is attributed to its fine grain size, minimal carbide presence, and unparalleled cleanliness. PM M4It offers a significant improvement in cutting tool longevity compared to the traditionally-manufactured M1,M2,M7and other lower-alloyed high-speed steels. Particularly excelling in cold work tooling applications, it outperforms 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/in^³ (7806 kg/m^³)

Specific Gravity

7.92

Modulus Of Elasticity

31 x 10 psi (214 GPa)

Machinability

40-45% of a 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), until reaching 1500-1600°F (816-871°C), then equalize.

Austenizing (High Heat):

Heat rapidly from the preheat.

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 achieve maximum toughness, use the lowest temperature. For optimal hot hardness, use the highest temperature.
Quenching:
Utilize pressurized gas, warm oil, or salt.

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

For oil quenching, heat until the steel turns black, approximately 900°F (482°C), then let it cool in still air to a temperature range of 150-125°F (66-51°C).

For salt quenching, maintain the temperature between 1000-1100°F (538-593°C). After equalizing the steel in the salt bath, allow it to cool in still air to 150-125°F (66-51°C).

Tempering:

Begin tempering immediately after quenching to ensure optimal results.
The ideal tempering temperature range is 1000-1100°F (538-593°C). Avoid tempering below 1000°F (538°C). Hold the steel at the desired temperature for 2 hours, then let it air cool to ambient temperature. For enhanced durability, double tempering is required. If the steel was austenitized at 2100°F (1149°C) or above, triple tempering is mandatory.

Annealing:

Annealing must be done post-hot working and before re-hardening to relieve stresses and restore ductility.

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