Specialty Graphites for the Metal Industry

Graphite Materials and systeMs

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Specialty Graphite and Process Solutions – made by SGL Group.

Advanced material, equipment, and process solutions

Engineered for customers from more than 35 industries

Tailor-made from the most comprehensive product portfolio

In-depth production and material knowledge

Consistent high quality, performance, and service

Attractive total cost of ownership

Broad Base. Best Solutions.

3Business unit Graphite Materials and systeMs

b Boring a crucible made from SIGRAFINE fine-grain graphite

Exceptional resistance to heat and corrosion, high purity and mechanical strength are just a few of the outstanding properties which our materials offer. Specialty graphite products from SGL Group achieve optimal results where other materials fail. No matter what your specific requirements might be, we will identify the best solution from the most comprehensive range of specialty graphites.

Fine grain graphite: isostatic, vibration- molded, die-molded, extruded

Expanded natural graphite Carbon fiber-reinforced carbon (C/C) Soft and rigid graphite felts Silicon carbide-coated graphite materials

Additionally we use other materials like PTFE, silicon carbide, and specialty metals.

With our portfolio and technical know-how spanning more than 35 different industries,

Advanced solutions enable our customers to get ahead.SGL Group offers advanced solutions – even for challenging applications. We understand the specific requirements of our customers and combine in-depth production, material, and engineering knowledge with the most comprehensive specialty graphite portfolio. This makes us the partner of choice to leading companies in many different industries.

we engineer tailor-made solutions in close partnership with our customers.

SGL Group covers the entire value chain of specialty graphite production, including raw material processing, semi-finished product manufacture, precision machining, purification, and coating. When it comes to engineering of equipment and process solutions our service range makes the difference: We offer mechanical and process design, production, assembly, commis-sioning, and service – all from a one-stop shop. This is how we control and ensure the consistent high quality, reliability, and performance of our products – and enable our customers to become more competitive. Challenge us. We are there for you worldwide.

Specialty graphite solutions for the metal industry

Innovative specialty graphite solutions help our customers in the metal industry in many areas: from casting and purification processes for pure metals and alloys to sintering processes in the powder metal industry. With optimized materials, we are a partner of choice to leading companies.

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Specialty graphites – made by SGL Group.Solutions for the metal industry.

�+�SIGRAFINE® is the new brand name for our fine-grain graphites, previously known under the names RINGSDORFF®, SIGRAFORM®, SIGRAMENT®, and CRYSTA-SIL®.

Materials made of carbon and graphite

Products of the SGL Group

SIGRAFINE® Isostatic, vibration-molded, die-moldedand extruded graphites

Graphite crucibleCooling system

Graphite die

Withdrawal unit

Horizontal castingApplications

Cooling plates Dies Crucibles Casting molds Semi-finished products (round/rectangular material)

For our customers in the metal industry, everything revolves around melting, casting, and shaping at very high tempera-tures. With the increasing demands on material purity,

product lifetime, and cost efficiency, the requirements for com-ponents and systems are becoming ever more challenging. The focus is increasingly on specialty graphites.

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SGL Group is proud to be able to offer the metal industry best solutions, even for the most challenging tasks. With our innovative, high-performance materials, we support the development of this industry.Our manifold materials are appreciated for their outstanding technical properties and ability to meet the highest require-ments in terms of quality, cost efficiency, and eco-friendliness: from achieving extremely high purity to simplifying machining, and saving on flushing gas. In numerous applications, our specialty graphites enhance the performance of systems and processes.

For consistent quality, every stage of our production is strictly monitored. Every block is tested and documented. These measures range from thorough incoming goods inspec-tions and raw materials testing to continuous monitoring of process parameters and sampling from each individual block that leaves the production process. In addition, clear identifi-cation codes make it possible to trace the provenance of each product every step of the way.

SIGRAFINE® isostatic, vibration-molded, die-molded and extruded graphites

Vertical casting (furnace-dependent)

Cooling plates Dies Crucibles Casting molds Semi-finished products (round/rectangular material)

SIGRAFINE® isostatic, vibration-molded and extruded graphites

Degassing systems

Gas injection tubesRotary gas distribution systems Casting rings Ladle liningsTapping spouts

Graphite crucible

Graphite die

Withdrawal unit

Graphite gas injection tube

Graphite ladle lining

Cooling systemSpout

�+�Video: isostatic graphite, a key product for the high-tech industry.

sglgroup

specialty Graphite solutions for the Metal industry

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Specialty graphites for continuous castingGraphite materials offer a range of advan-tageous properties that can prove benefi-cial in many metallurgical applications, such as continuous casting:

Excellent thermal shock resistance

High chemical and thermal resistance

Increasing flexural strength with rising temperature

Adjustable thermal conductivity for optimized slip properties

7specialty Graphites for continuous castinG

SIGRAFINE® fine-grain graphites for dies and crucibles

b Vertical down casting of precisious metal alloy, melting in a graphite crucible and typical continuous casting graphite dies

Continuous casting of non-ferrous metals, precious metals, and iron is a widely used process. It offers non-stop produc-tion and ensures high material quality. Thanks to their high thermal conductivity, our isostatic specialty graphites enable rapid, targeted solidification of metal alloys. For vertical continuous casting, large molds, and low through-put, extruded graphites, such as SIGRAFINE HLM, can also be used as a material for pressure components. In addition, numerous synthetic graphite powders are available as car-burizing agents.

For dies and crucibles, extruded and vibration-molded graphites are used, depending on the size. Thermal shock resistance, consistently high purity, and high material density with low porosity guarantee excellent melting processes.

SIGRAFINE fine-grain graphites are tailored to specific alloying requirements. With critical metal alloys in mind, we have developed special isostatically pressed graphites with high mechanical strength and density. We supply them as semi-finished products but also make crucibles and dies from them to suit individual requirements.

Recommended use of SIGRAFINE® isostatic graphites for metal alloy dies

Alloy Shape R4340 R4500 R4550 R4810 R4820

CuZnround

strip wire

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○

○ ○

○ ○

CuSnround

strip wire

○

○

○ ○

○ ○ ○

○ ○

CuNiZnround

strip wire

○ ○ ○

○ ○ ○

CuNiround

strip wire

○ ○ ○

○ ○ ○

Ag alloysround

strip wire

○ ○ ○

○ ○ ○

○ ○ ○

○ ○ ○

○ ○ ○

Au alloysround

strip wire

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○ ○ ○

○ ○ ○

○ ○ ○

○ ○ ○

Gray cast iron/spheroidal cast iron ○ ○

Other grades on request. Please contact us. Material data and dimensions can be found on page 8.

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The thermal conductivity of graphite is higher than that of many metals and decreases with rising temperature. The thermal expansion coefficient of many graphite grades is only

one quarter that of iron. Thermal conductivity and thermal expansion can be adjusted by appropriate selection and pro-cessing of the raw material or by the degree of graphitization.

Material data for SIGRAFINE® isostatic graphites

Typical properties Units R4340 R4500 R4550 R4810 R4820Average grain size µm 15 10 10 20 20Bulk density g /cm³ 1.72 1.77 1.83 1.82 1.82Open porosity Vol. % 15 14 10 11 10Average pore size µm 2.2 1.8 1.8 3.3 2.0Coefficient of permeability (20 °C) cm²/s 0.25 0.25 0.06 0.30 0.15Rockwell hardness HR ₁₀ / ₁₀₀ 80 HR ₅ / ₁₀₀ 70 HR ₅ / ₁₀₀ 90 HR ₁₀ / ₁₀₀ 95 HR ₁₀ / ₁₀₀ 100Flexural strength MPa 45 50 60 45 50Compressive strength MPa 90 110 130 100 105Dynamic modulus of elasticity GPa 11.0 10.5 11.5 10.5 11.0Thermal conductivity (20 °C) Wm-¹K-¹ 105 90 105 140 125Thermal expansion (20 – 200 °C) 10-⁶K-¹ 3.2 4.2 4.2 4.1 4.2Ash content % 0.02 0.02 0.002 0.005 0.01

Ther

mal

con

duct

ivity

[%]

Temperature [K]

Typical thermal conductivity of graphite

0

40

60

20

80

100

500 2000 30001000

Ther

mal

exp

ansi

on �

1)

Temperature [K]

Typical thermal expansion of graphite

0

1.0

1.5

0.5

2.0

500 2000 30001000

1) amount X added to

Other grades and dimensions on request. Please contact us.You will find the US-units in the data sheet enclosed with the brochure.

Standard dimensions of SIGRAFINE® isostatic graphites for continuous casting

R4340 R4500 R4550 R4810 R4820

1550 x 410 x 200 mm 1230 x 500 x 400 mm

610 x 500 x 400 mm

1230 x 500 x 400 mm 610 x 500 x 400 mm

1230 x 500 x 400 mm 610 x 500 x 400 mm

1230 x 510 x 330 mm 610 x 510 x 330 mm

1230 x 510 x 330 mm 610 x 510 x 330 mm

Ø 150 – 420 x 1230 mm Ø 380 x 520 mm

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Development partnership leads to new materialIn close collaboration with OEMs and end users in the copper and copper alloy industry, we have developed the specialty graphite SIGRAFINE R4820 for casting dies. The important advan tages of this innovative material are:

Lower oxidation

Faster casting rate

Better mechanical wear strength

This is just one example of an application- specific optimized solution from the SGL Group.

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Specialty graphites for die casting and sinteringGraphite materials and components are being increasingly used in the metal indus-try for die casting and sintering processes. In these applications, graphite offers the following particular advantages:

High resistance to temperature change

Extremely high compressive strength

Increasing flexural strength with rising temperature

Low wettability and adhesive tendency

Good porosity

11specialty Graphites for die castinG and sinterinG

SIGRAFINE® fine-grain graphites for molds

b SIGRAFINE graphite molds for pressure sintering

Railroad wheels and diamond drill bits are typical die-cast and sintered products. Our carbons and extruded, vibration- molded, and die-molded graphites are highly suitable for the complex molds used to produce such components. These

specialty graphites are robust and have a long service life thanks to their material properties.With our comprehensive range of materials, we cover all material property and size requirements.

For casting railroad wheels, we have developed special vibration-molded and die-molded graphites. These materials, sold under the brand name SIGRAFINE, are primarily charac-ter ized by good permeability and high mechanical strength. We supply them as semi-finished products but also make large-format casting molds from them, tailored to individual requirements.

c Large graphite round formats used as casting molds for railroad wheels

c Extruded graphite round formats e.g. for casting diamond drill bits

For components used to produce diamond drill bits, we sup-ply special extruded and isostatically pressed graphites. The wide range of materials sold under the SIGRAFINE brand name caters for both tungsten carbide powder production and prototype molds. The extruded graphites are highly suitable for e.g. moldmaking, while the isostatically pressed graphites are used specially for molds to create the intricate recesses in drill bits and for cutting tools.

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II parallel to the grain direction.Other grades and dimensions on request. Please contact us.You will find the US-units in the data sheet enclosed with the brochure.

Spec

ific

heat

[J/g

K]

Temperature [K]

Specific heat of graphite

0.5

1.5

2.0

1.0

2.5

500 2000 30001000

Mec

hani

cal s

tren

gth

[%]

Temperature [K]

Mechanical strength of graphite

0

100

50

150

200

500 2000 30001000

Unlike with most materials, the tensile, compressive, and flexural strength values of graphites increase with rising tem-perature up to 2700 K, beyond which they start to fall again. At 2700 K, graphite is twice as strong as at room temperature.

Our graphite grades differ only slightly in their temperature-dependent specific heat value.

Material data for SIGRAFINE® HMR die-molded graphite Typical application: molds for railroad wheels

Typical properties

Standard dimensions of HMR

Units

Ø 1090 x 585 mm Ø 1220 x 585 mmØ 1395 x 585 mm

Bulk density g /cm³ 1.65Max. particle size mm 0.8Flexural strength (3 pt) MPa II 16.9Thermal conductivity (20 °C) Wm-¹K-¹ II 116Thermal expansion (100 – 600 °C) 10-⁶K-¹ II 3.61Rockwell hardness II 23Ash content % < 0.1Iron content ppm < 200

13specialty Graphites for die castinG and sinterinG

II parallel to the grain direction; I– perpendicular to the grain direction.Other grades and dimensions on request. Please contact us.You will find the US-units in the data sheet enclosed with the brochure.

c Boats made from SIGRAFINE fine-grain graphite for thermal treatment in the powder metal industry

Material data for SIGRAFINE® MKUN vibration-molded graphite. Typical application: large-size casting troughs for metal melts Material data for SIGRAFINE® HLM extruded graphite. Typical application: molds for diamond boring heads

Standard dimensions of MKUN Standard dimensions of HLM

Typical properties

Units

Ø 760 – 960 x 1000 mmØ 1150 – 1550 x 600 mm

Ø 1685 x 550 mm610 x 720 x 2700 mm

630 x 1300 x 1420 mm

Ø 400 – 780 x 1830 mm 500 x 500 x 3300 mm600 x 600 x 3300 mm

Bulk density g /cm³ 1.66 1.72Max. particle size mm 0.8 0.8

Dynamic modulus of elasticity GPa II I–

7 6

9 7

Flexural strength MPa II I–

3 pt 9 3 pt 9

4 pt 19 4 pt 19

Compressive strength MPa II I–

23 23

40 39

Tensile strength MPa II I–

6 6

13 13

Thermal expansion (20 – 200 °C) 10-⁶K-¹ II I–

2.3 3.1

3.0 3.5

Ash content % 0.07 0.08

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Typical components for degassing systemsFor efficient degassing processes with maximum purification, gas injection and distribution systems designed to suit specific plant conditions play a crucial role.

On the basis of their specific plant pa-rameters, we help our customers design, produce, and operate optimum degassing systems.

15specialty Graphites for deGassinG systeMs

SIGRAFINE® fine-grain graphites for degassing systems and casting rings

b Purification tube made from SIGRAFINE HLM for treating molten metals

Graphite offers considerable advantages over other mate-rials thanks to its material properties such as thermal shock resistance, corrosion resistance, and virtually zero wettability by metal melts. It is therefore highly suitable for degassing processes and is used to remove hydrogen and oxidic impuri-ties from aluminum and aluminum alloy melts.

The entire aluminum processing chain benefits from the typical properties of graphite:from high oxidation resistance and low abrasion during melt-ing and degassing to mechanical efficiency, low wear, and high thermal shock resistance during casting. Application-specific materials ensure cost-efficient operation with optimum results.

We work closely with OEMs supplying the aluminum pro-cessing industry.For example, in collaboration with customers, we have devel-oped casting rings made from isostatic graphite R4800 that are used in the production of aluminum billets. Our material was chosen because of its uniform pore distribution.

c SIGRAFINE casting rings for the production of aluminum billets

c SIGRAFINE MTS gas injection tubes

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Materials for gas injection tubes and rotary distribution sys-tems must withstand extreme stresses, e.g. rapid temperature changes, high operating temperatures, contact with molten metal, highly corrosive flushing gas, and alloy constituents.

We supply selected materials for degassing tubes and gas distribution systems used in non-ferrous metal melts. Our SIGRAFINE materials allow plant-specific design of gas injection systems for batch-operated and continuous plants of any size, irrespective of output rate.

Specialty graphites for degassing tubes and gas distribution systems

c SIGRAFINE rotor heads for rotary gas distribution systems

c Crucible and rotary gas distribution systems made from SIGRAFINE fine-grain graphite

17specialty Graphites for deGassinG systeMs

For gas injection tubes, SIGRAFINE MTN and HLM should preferably be used. The reason for this is the high oxidation rate. For specific requirements, we supply an additional special impregnation (NOX treatment) that further increases the oxidation protec-tion and lifetime of the materials.

oxidation-protected

unprotected

Rela

tive

oxid

atio

n ra

te

Temperature [K]

Oxidation rates of gas injection tubes

0

15

5

10

25

20

30

970 1020870 1070920C

onta

ct s

urfa

ce/li

ter g

as [m

2]Gas bubble diameter [mm]

Effective surface of the flushing gas

0

3

1

2

5

4

6

8 12 16 204

Material data for SIGRAFINE® MTN extruded graphiteTypical application: degassing systems

Typical properties UnitsStandard dimensions of MTN

Ø 50/12 x 3000 mmBulk density g /cm³ 1.62Max. particle size mm 0.4Open porosity Vol. % 24

Dynamic modulus of elasticity GPa II 12Flexural strength (4 pt) MPa II 18

Compressive strength MPa II I–

25 25

Tensile strength MPa II 10Thermal expansion (20 – 200 °C) 10-⁶K-¹ II 0.8Coefficient of permeability (20 °C) cm²/s 0.5Thermal conductivity (20 °C) Wm-¹K-¹ II 160Ash content % 0.15

II parallel to the grain direction; I– perpendicular to the grain direction.Other grades and dimensions on request. Please contact us.You will find the US-units in the data sheet enclosed with the brochure.

Gas injection systems made from SIGRAFINE achieve very high degrees of purity with lower gas consumption. Gas injection with graphite tubes or rotary distribution systems produces very fine gas bubbles. This increases the effective surface of the flushing gas. In addition, it reduces the rate of gas bubble rise, which means that the flushing gas remains longer in contact with the melt. Through this fine gas distribution, graphite tubes enable far more effective melt purification, so that much less gas is required to achieve comparable results.

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We will find the best solution – in partnership with you.The fascinating potential of carbon as a material excites us and inspires us to develop optimum solutions in partnership with our customers.

With our comprehensive material portfolio and valuable specialist know-how, we can manufacture tailored products – even for the most challenging applications.

Consistently high quality, a global presence, innovative strength, and the extensive experience of our employees make us a reliable partner to our customers.

Whatever challenges you face, together we will find the best solution.

19sGl Group – the carBon coMpany

b Quality testing of a SIGRAFINE strip die

SGL Group – The Carbon Company. A leading global manufacturer of carbon-based products.

Unique product portfolio Innovative technologies and solutions Production sites close to sales markets Technology & Innovation Center in Germany with international networks

We have wide-ranging expertise in raw materials,advanced manufacturing processes, and long-standing application and engineering know-how. We have a comprehensive portfolio of carbon,graphite, and carbon fiber products and ourintegrated value chain covers everything fromcarbon fiber to composites. With a global sales anddistribution network and modern production sitesin Europe, North America, and Asia, we are close toour customers throughout the world.

We use this broad base to offer our customers thebest solutions possible. That's how we live up to our claim: Broad Base. Best Solutions. This claim is also upheld by our corporate SGL Excellence philosophy of continuous improvement.

�+�More information can be found by visiting: www.sglgroup.com

sglgroup sglgroup

Contact

europe/Middle east/africaSGL CARBON GmbHDrachenburgstrasse 153170 Bonn/Germanygms-europe@sglgroup.com

asia/pacificSGL CARBON Far East Ltd.12 Fl, Shanghai Oriental Plaza 31 Wujiang Road Shanghai 200041/PR Chinagms-asia@sglgroup.com

Picture credits: Allgemeine Gold- und Silberscheideanstalt AG, Pforzheim/Germany (page 6)SM Sächsisches Metallwerk Freiberg GmbH, Freiberg/Germany (page 9)

aMericasSGL CARBON LLC900 Theresia StreetPA 15857 St. Marys/USAgms-americas@sglgroup.com

® registered trademarks of SGL CARBON SE 07 2015/0  2NÄ Printed in GermanyThis information is based on our present state of knowledge and is intended to provide general notes on our products and their uses. It should therefore not be construed as guaranteeing specific properties of the prod-ucts described or their suitability for a particular application. Any existing industrial property rights must be observed. The quality of our products is guaranteed under our “General Conditions of Sale”.

Graphite Materials & SystemsSGL CARBON GmbH Soehnleinstrasse 8 | 65201 Wiesbaden/Germanywww.sglgroup.com/gms