S2 Powder

Overview of S2 Powder

S2 powder is a high speed tool steel powder ideal for making cutting tools requiring high hardness, strength, and wear resistance at elevated temperatures. It contains tungsten, molybdenum, vanadium, and additional alloys providing excellent hot hardness and thermal fatigue resistance.

Key properties and advantages of S2 powder:

S2 Powder Properties and Characteristics

Properties	Details
Composition	Fe-1C-5Cr-2.35Mo-6.4W-1.4V-2Si alloy
Density	7.7 g/cc
Particle shape	Irregular, angular
Size range	10-150 microns
Apparent density	Up to 50% of true density
Flowability	Low to moderate
Hardness	62-64 HRC when heat treated
Toughness	Very good

S2 powder produces cutting tools, dies, and machine components with extended service life under continuous high temperature and intermittent shock loading conditions.

S2 Powder Composition

Typical composition of S2 high speed steel powder:

S2 Powder Composition

Element	Weight %
Iron (Fe)	Balance
Carbon (C)	0.9-1.2%
Chromium (Cr)	3.8-4.5%
Tungsten (W)	6.4%
Molybdenum (Mo)	1.9-2.2%
Vanadium (V)	1.3-1.6%
Manganese (Mn)	0.2-0.5%
Silicon (Si)	0.9-1.4%

• Iron provides the ferritic matrix
• Carbon, tungsten, and chromium form hard carbides
• Vanadium and molybdenum enhance wear resistance
• Manganese and silicon facilitate machining

The composition is optimized to achieve an exceptional combination of hot hardness, red hardness, and toughness necessary for high speed machining applications.

S2 Powder Physical Properties

S2 Powder Physical Properties

Property	Values
Density	7.7 g/cc
Melting point	1320-1350°C
Thermal conductivity	37 W/mK
Electrical resistivity	0.6 μΩ-m
Maximum service temperature	600°C
Curie temperature	770°C

• High density enables miniaturized components
• Retains hardness and strength at elevated temperatures
• Becomes paramagnetic above Curie point
• Can withstand prolonged service up to 600°C
• Good thermal conductivity reduces thermal expansion stresses

These properties provide a balanced combination of hot hardness and thermal shock resistance required in high speed machining applications.

S2 Powder Mechanical Properties

S2 Powder Mechanical Properties

Property	Values
Hardness	62-64 HRC
Transverse rupture strength	4500-4800 MPa
Compressive strength	3800-4100 MPa
Tensile strength	2050-2250 MPa
Yield strength	1930-2050 MPa
Elongation	8-10%
Impact toughness	10-14 J/cm2

• Exceptional hardness when heat treated
• High strength with reasonable ductility
• Very good compressive and transverse rupture strength
• Excellent red hardness at elevated temperatures
• Strength depends on heat treatment process

S2 powder produces cutting tools and dies with hardness, strength, and thermal properties needed to machine challenging materials at high speeds and temperatures.

S2 Powder Applications

Typical applications of S2 high speed steel powder include:

S2 Powder Applications

Industry	Example Uses
Automotive	Cutting and milling tools
Aerospace	Drills, end mills
Manufacturing	Punches, forming dies
Oil and gas	Downhole tools, drill bits
General machining	Turning, boring, and planing tools

Some specific product uses:

• Cutting inserts, indexable tooling
• Broaches, reamers, taps, threading dies
• Metal slitting saws and industrial knives
• Extrusion tooling and drawing dies
• Cold heading and forging dies
• Gauges, wear-resistant components

S2’s unique properties make it the top choice for reliable cutting tools and components used in demanding metalworking applications.

S2 Powder Specifications

Key specifications for S2 high speed steel powder:

S2 Powder Standards

Standard	Description
ASTM A600	Specification for tool steels high speed steel
JIS G4403	High speed tool steels
DIN 1.2363	Equivalent to AISI S7 high speed steel
UNS T11302	Designation for AISI S2 grade
ISO 4957	Tool steels specification

These define:

• Chemical composition limits of S2
• Required mechanical properties in heat treated condition
• Approved production methods like gas atomization
• Compliance testing protocols
• Quality assurance requirements
• Proper packaging and identification

Powder produced to these standards ensures suitability for high wear resistance tooling applications under thermal fatigue conditions.

S2 Powder Particle Sizes

S2 Powder Particle Size Distribution

Particle Size	Characteristics
10-22 microns	Ultrafine grade provides highest density
22-53 microns	Most commonly used size range
53-105 microns	Coarser size provides good flowability

• Finer particles allow greater densification during sintering
• Coarser particles improve powder flow into die cavities
• Size is selected based on final part properties needed
• Both gas and water atomized particles used

Controlling size distribution optimizes pressing behavior, sintered density, and final component performance.

S2 Powder Apparent Density

S2 Powder Apparent Density

Apparent Density	Details
Up to 50% of true density	For irregular powder morphology
4.0-5.0 g/cc	Higher for spherical, lower for irregular powder

• Spherical powder shape provides high apparent density
• Irregular powder has lower density around 45-50%
• Higher apparent density improves die filling and part quality
• Allows complex tool geometry compaction

Higher apparent density leads to better component production rate and performance.

S2 Powder Production Method

S2 Powder Production

Method	Details
Gas atomization	High pressure inert gas breaks up molten alloy stream into fine droplets
Vacuum induction melting	High purity input materials melted under vacuum
Multiple remelting	Enhances chemical homogeneity
Sieving	Classifies powder into different particle size fractions

• Gas atomization provides spherical powder shape
• Vacuum melting eliminates gaseous impurities
• Multiple remelting improves uniformity
• Post-processing allows particle size customization

Fully automated processes combined with strict quality control ensures reliable and consistent S2 powder properties critical for tooling performance.

S2 Powder Pricing

S2 Powder Pricing

Factor	Impact on Price
Purity level	Higher purity grades cost more
Particle size	Ultrafine powder more expensive
Order quantity	Price decreases with larger volumes
Additional services	Customization adds cost

Indicative Pricing

• S2 spherical powder: $18-22 per kg
• S2 irregular powder: $12-16 per kg
• Large volume pricing up to 30% lower

Pricing depends on purity, particle characteristics, order quantity, and any additional customization requirements.

S2 Powder Suppliers

S2 Powder Suppliers

Company	Location
Höganäs	Sweden
Carpenter Powder Products	USA
Erasteel	USA, Europe
Crucible Industries	USA
voxco	Germany
Jingdong New Materials	China

Key supplier selection factors:

• Powder grades offered
• Production capacity
• Particle characteristics and consistency
• Testing capability and quality control
• Pricing and lead times
• Technical customer service

S2 Powder Handling and Storage

S2 Powder Handling

Recommendation	Reason
Ensure proper ventilation	Prevent exposure to fine metal particles
Use appropriate PPE	Avoid ingestion through nose/mouth
Ground equipment	Prevent static sparking
Avoid ignition sources	Flammable dust hazard
Use non-sparking tools	Prevent possibility of ignition
Follow safe protocols	Reduce fire, explosion, health risks

Storage Recommendations

• Store sealed containers away from moisture or contamination
• Maintain storage temperatures below 27°C
• Limit exposure to oxidizing acids and chlorine compounds

Proper precautions during handling and storage help preserve purity and prevent safety hazards.

S2 Powder Inspection and Testing

S2 Powder Testing

Test	Details
Chemical analysis	Verifies composition using optical/ICP spectroscopy
Particle size analysis	Determines size distribution using laser diffraction or sieving
Apparent density	Measured as per ASTM B212 using Hall flowmeter
Powder morphology	SEM imaging to determine particle shape
Flow rate test	Gravity flow rate through specified funnel
Tap density test	Density measured after mechanically tapping powder sample

Testing ensures the powder meets the required chemical composition, physical characteristics, particle size distribution, morphology, density, and flow rate specifications.

S2 Powder Pros and Cons

Advantages of S2 Powder

• Exceptional hot hardness and red hardness
• High strength and wear resistance at elevated temperatures
• Good toughness and thermal shock resistance
• Resists softening and shape changes up to 600°C
• Dimensional stability under thermal cycling
• Cost-effective compared to exotic PM tool steel grades

Limitations of S2 Powder

• Moderate corrosion resistance without surface treatment
• Limited cold formability and shear strength
• Requires careful heat treatment by experienced providers
• Not weldable using conventional fusion welding
• Large cross-sections can experience embrittlement
• Contains expensive alloying elements

Comparison With H13 Tool Steel Powder

S2 vs H13 Tool Steel Powder

Parameter	S2	H13
Hardness	62-64 HRC	54-57 HRC
Hot hardness	Excellent	Good
Toughness	Very good	Good
Thermal shock resistance	Excellent	Moderate
Cold strength	Good	Excellent
Cost	High	Low

• S2 has much greater hot hardness and thermal shock resistance
• H13 provides better cold strength and toughness
• S2 is more expensive due to higher alloy content
• S2 preferred for high speed machining applications
• H13 suited for cold and warm pressing tooling

S2 Powder FAQs

Q: What are the main applications of S2 tool steel powder?

A: Main applications include cutting tools like drills, mills, inserts, taps, dies, saws, planing tools, as well as extrusion tooling, forging dies, gauges, and components needing hot hardness and thermal shock resistance.

Q: What heat treatment is used for S2 tool steel powder?

A: S2 tool steel is typically heat treated by austenitizing between 1150-1200°C followed by air, oil, or polymer quenching, then tempering between 540-650°C to achieve hardness between 62-64 HRC.

Q: How does tungsten improve the properties of S2 steel?

A: Tungsten forms hard tungsten-iron-carbon complexes that provide exceptional hot hardness, strength and wear resistance at elevated temperatures needed for high speed machining applications.

Q: What safety precautions should be used when working with S2 powder?

A: Proper ventilation, protective gear, inert atmosphere, grounding, avoiding ignition sources, using non-sparking tools, and safe storage away from contamination or moisture.