Graphite Materials and Systems
Specialty
Graphites
for the Metal
Industry
2
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.
Business Unit Graphite Materials and Systems
3
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.
Exceptional resistance to heat and corrosion, high
we engineer tailor-made solutions in close
purity and mechanical strength are just a few of
partnership with our customers.
the outstanding properties which our materials
offer. Specialty graphite products from SGL Group
SGL Group covers the entire value chain of
achieve optimal results where other materials fail.
specialty graphite production, including raw
No matter what your specific requirements might
material processing, semi-finished product
be, we will identify the best solution from the most
manufacture, precision machining, purification,
comprehensive range of specialty graphites.
and coating. When it comes to engineering of
equipment and process solutions our service
̤̤ Fine grain graphite: isostatic, vibrationmolded, die-molded, extruded
range makes the difference: We offer mechanical
and process design, production, assembly, commis-
̤̤ Expanded natural graphite
sioning, and service – all from a one-stop shop.
̤̤ Carbon fiber-reinforced carbon (C/C)
This is how we control and ensure the consistent
̤̤ Soft and rigid graphite felts
high quality, reliability, and performance of our
̤̤ Silicon carbide-coated graphite materials
products – and enable our customers to become
more competitive. Challenge us. We are there for
Additionally we use other materials like PTFE,
you worldwide.
silicon carbide, and specialty metals.
Specialty graphite solutions for the metal industry
With our portfolio and technical know-how
spanning more than 35 different industries,
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
b Boring a crucible made from
SIGRAFINE fine-grain graphite
powder metal industry. With optimized materials,
we are a partner of choice to leading companies.
4
Specialty graphites – made by SGL Group.
Solutions for the metal industry.
For our customers in the metal industry, everything revolves
product lifetime, and cost efficiency, the requirements for com-
around melting, casting, and shaping at very high tempera-
ponents and systems are becoming ever more challenging. The
tures. With the increasing demands on material purity,
focus is increasingly on specialty graphites.
+ SIGRAFINE® is the new brand name
for our fine-grain graphites, previously known
under the names RINGSDORFF®, SIGRAFORM®,
SIGRAMENT®, and CRYSTA-SIL®.
Graphite crucible
Cooling system
Withdrawal unit
Graphite die
Applications
Horizontal casting
Materials made of
carbon and graphite
SIGRAFINE®
Isostatic, vibration-molded, die-molded
and extruded graphites
Products
of the SGL Group
Cooling plates
Dies
Crucibles
Casting molds
Semi-finished products
(round/rectangular material)
SPECIALTy GRAPHITE solutions FOR THE METAL INDUSTRY
5
SGL Group is proud to be able to offer the metal industry
For consistent quality, every stage of our production is
best solutions, even for the most challenging tasks. With
strictly monitored. Every block is tested and documented.
our innovative, high-performance materials, we support the
These measures range from thorough incoming goods inspec-
development of this industry.
tions and raw materials testing to continuous monitoring of
Our manifold materials are appreciated for their outstanding
process parameters and sampling from each individual block
technical properties and ability to meet the highest require-
that leaves the production process. In addition, clear identifi-
ments in terms of quality, cost efficiency, and eco-friendliness:
cation codes make it possible to trace the provenance of each
from achieving extremely high purity to simplifying machining,
product every step of the way.
and saving on flushing gas. In numerous applications, our
specialty graphites enhance the performance of systems and
processes.
+ Video: isostatic graphite, a key product
for the high-tech industry.
sglgroup
Graphite crucible
Spout
Cooling system
Graphite gas injection tube
Graphite die
Graphite ladle lining
Withdrawal unit
Vertical casting (furnace-dependent)
Degassing systems
SIGRAFINE®
isostatic, vibration-molded, die-molded
and extruded graphites
SIGRAFINE®
isostatic, vibration-molded
and extruded graphites
Cooling plates
Dies
Crucibles
Casting molds
Semi-finished products
(round/rectangular material)
Gas injection tubes
Rotary gas distribution systems
Casting rings
Ladle linings
Tapping spouts
6
Specialty graphites for
continuous casting
Graphite materials offer a range of advantageous properties that can prove beneficial 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
SPECIALTy GRAPHITEs FOR CONTINUOUS CASTING
7
SIGRAFINE® fine-grain graphites
for dies and crucibles
Continuous casting of non-ferrous metals, precious metals,
For dies and crucibles, extruded and vibration-molded
and iron is a widely used process. It offers non-stop produc-
graphites are used, depending on the size.
tion and ensures high material quality.
Thermal shock resistance, consistently high purity, and high
Thanks to their high thermal conductivity, our isostatic
material density with low porosity guarantee excellent
specialty graphites enable rapid, targeted solidification of
melting processes.
metal alloys.
For vertical continuous casting, large molds, and low through-
SIGRAFINE fine-grain graphites are tailored to specific
put, extruded graphites, such as SIGRAFINE HLM, can also
alloying requirements.
be used as a material for pressure components. In addition,
With critical metal alloys in mind, we have developed special
numerous synthetic graphite powders are available as car­
isostatically pressed graphites with high mechanical strength
burizing agents.
and density. We supply them as semi-finished products but
also make crucibles and dies from them to suit individual
requirements.
b Vertical down casting of precisious metal alloy,
melting in a graphite crucible and
typical continuous casting graphite dies
Recommended use of SIGRAFINE® isostatic graphites for metal alloy dies
Alloy
Shape
CuZn
round
strip
wire
○
○
CuSn
round
strip
wire
○
○
CuNiZn
round
strip
wire
○
○
○
○
○
○
CuNi
round
strip
wire
○
○
○
○
○
○
Ag alloys
round
strip
wire
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
Au alloys
round
strip
wire
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
○
Gray cast iron/spheroidal cast iron
Other grades on request. Please contact us.
Material data and dimensions can be found on page 8.
R4340
R4500
R4550
R4810
○
○
○
○
○
○
R4820
○
○
○
○
○
8
The thermal conductivity of graphite is higher than that of
one quarter that of iron. Thermal conductivity and thermal
many metals and decreases with rising temperature. The
expansion can be adjusted by appropriate selection and pro-
thermal expansion coefficient of many graphite grades is only
cessing of the raw material or by the degree of graphitization.
Typical thermal conductivity of graphite
Typical thermal expansion of graphite
2.0
100
1.5
Thermal expansion 1)
Thermal conductivity [%]
80
60
40
20
0
500
1000
2000
1.0
0.5
0
3000
2000
1000
500
3000
Temperature [K]
Temperature [K]
1) amount X added to 
Material data for SIGRAFINE® isostatic graphites
Typical properties
Units
R4340
R4500
R4550
R4810
R4820
Average grain size
µm
15
10
10
20
20
Bulk density
g /cm³
1.72
1.77
1.83
1.82
1.82
Open porosity
Vol. %
15
14
10
11
10
µm
2.2
1.8
1.8
3.3
2.0
Average pore size
Coefficient of permeability (20 °C)
cm²/s
Rockwell hardness
0.25
0.25
0.06
0.30
0.15
HR ₁₀ / ₁₀₀ 80
HR ₅ / ₁₀₀ 70
HR ₅ / ₁₀₀ 90
HR ₁₀ / ₁₀₀ 95
HR ₁₀ / ₁₀₀ 100
45
50
60
45
50
Flexural strength
MPa
Compressive strength
MPa
90
110
130
100
105
Dynamic modulus of elasticity
GPa
11.0
10.5
11.5
10.5
11.0
Wm-¹K-¹
105
90
105
140
125
10-⁶K-¹
3.2
4.2
4.2
4.1
4.2
%
0.02
0.02
0.002
0.005
0.01
Thermal conductivity (20 °C)
Thermal expansion (20 – 200 °C)
Ash content
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
Other grades and dimensions on request. Please contact us.
You will find the US-units in the data sheet enclosed with the brochure.
Ø 380 x 520 mm
9
Development partnership
leads to new material
In 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 advan­tages of this
innovative material are:
̤̤ Lower oxidation
̤̤ Faster casting rate
̤̤ Better mechanical wear strength
This is just one example of an applicationspecific optimized solution from the
SGL Group.
10
Specialty graphites for
die casting and sintering
Graphite materials and components are
being increasingly used in the metal industry 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
SPECIALTy GRAPHITEs FOR DIE CASTING AND SINTERING
11
SIGRAFINE® fine-grain graphites
for molds
Railroad wheels and diamond drill bits are typical die-cast
specialty graphites are robust and have a long service life
and sintered products. Our carbons and extruded, vibration-
thanks to their material properties.
molded, and die-molded graphites are highly suitable for the
With our comprehensive range of materials, we cover all
complex molds used to produce such components. These
material property and size 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 casting railroad wheels, we have developed special
For components used to produce diamond drill bits, we sup-
vibration-molded and die-molded graphites. These materials,
ply special extruded and isostatically pressed graphites.
sold under the brand name SIGRAFINE, are primarily charac­
The wide range of materials sold under the SIGRAFINE brand
ter­ized by good permeability and high mechanical strength.
name caters for both tungsten carbide powder production and
We supply them as semi-finished products but also make
prototype molds. The extruded graphites are highly suitable
large-format casting molds from them, tailored to individual
for e.g. moldmaking, while the isostatically pressed graphites
requirements.
are used specially for molds to create the intricate recesses in
drill bits and for cutting tools.
b SIGRAFINE graphite molds
for pressure sintering
12
Unlike with most materials, the tensile, compressive, and
Our graphite grades differ only slightly in their temperature-
flexural strength values of graphites increase with rising tem-
dependent specific heat value.
perature up to 2700 K, beyond which they start to fall again.
At 2700 K, graphite is twice as strong as at room temperature.
Specific heat of graphite
200
2.5
150
2.0
Specific heat [J/gK]
Mechanical strength [%]
Mechanical strength of graphite
100
50
0
500
1000
2000
3000
1.5
1.0
0.5
500
Temperature [K]
1000
2000
3000
Temperature [K]
Material data for SIGRAFINE® HMR die-molded graphite
Typical application: molds for railroad wheels
Standard dimensions of HMR
Units
Ø 1090 x 585 mm
Ø 1220 x 585 mm
Ø 1395 x 585 mm
g /cm³
1.65
Typical properties
Bulk density
Max. particle size
mm
Flexural strength (3 pt)
MPa
II
Wm-¹K-¹
II
116
10 -⁶K-¹
II
3.61
II
23
Thermal conductivity (20 °C)
Thermal expansion (100 – 600 °C)
Rockwell hardness
0.8
16.9
Ash content
%
< 0.1
Iron content
ppm
< 200
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.
SPECIALTy GRAPHITEs FOR DIE CASTING AND SINTERING
13
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
Typical properties
Bulk density
Max. particle size
Standard dimensions of MKUN
Standard dimensions of HLM
Units
Ø 760 – 960 x 1000 mm
Ø 1150 – 1550 x 600 mm
Ø 1685 x 550 mm
610 x 720 x 2700 mm
630 x 1300 x 1420 mm
Ø 400 – 780 x 1830 mm
500 x 500 x 3300 mm
600 x 600 x 3300 mm
g /cm³
1.66
1.72
mm
0.8
0.8
7
6
9
7
Dynamic modulus of elasticity
GPa
II
–I
Flexural strength
MPa
II
–I
3 pt 9
3 pt 9
4 pt 19
4 pt 19
Compressive strength
MPa
II
23
23
40
39
Tensile strength
MPa
II
6
6
13
13
II
2.3
3.1
3.0
3.5
0.07
0.08
Thermal expansion (20 – 200 °C)
Ash content
10 -⁶K-¹
%
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.
–I
–I
–I
14
Typical components for
degassing systems
For 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 parameters, we help our customers design,
produce, and operate optimum degassing
systems.
SPECIALTy GRAPHITEs FOR DEGASSING SYSTEMS
15
SIGRAFINE® fine-grain graphites
for degassing systems and casting rings
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 impurities 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 melting and degassing to mechanical efficiency, low wear, and high
thermal shock resistance during casting. Application-specific
materials ensure cost-efficient operation with optimum
results.
c SIGRAFINE casting rings for the production
of aluminum billets
We work closely with OEMs supplying the aluminum processing industry.
For example, in collaboration with customers, we have developed 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 MTS gas injection tubes
b Purification tube made from SIGRAFINE HLM
for treating molten metals
16
Specialty graphites for degassing tubes
and gas distribution systems
Materials for gas injection tubes and rotary distribution systems 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.
c Crucible and rotary gas distribution systems
made from SIGRAFINE fine-grain graphite
c SIGRAFINE rotor heads for rotary
gas distribution systems
SPECIALTy GRAPHITEs FOR DEGASSING SYSTEMS
17
Effective surface of the flushing gas
Oxidation rates of gas injection tubes
6
Relative oxidation rate
25
Contact surface/liter gas [m2]
30
unprotected
20
15
10
oxidation-protected
5
0
870
920
970
1020
5
4
3
2
1
0
1070
4
Temperature [K]
8
12
16
20
Gas bubble diameter [mm]
For gas injection tubes, SIGRAFINE MTN and HLM should
Gas injection systems made from SIGRAFINE achieve very
preferably be used.
high degrees of purity with lower gas consumption.
The reason for this is the high oxidation rate. For specific
Gas injection with graphite tubes or rotary distribution
requirements, we supply an additional special impregnation
systems produces very fine gas bubbles. This increases the
(NOX treatment) that further increases the oxidation protec-
effective surface of the flushing gas. In addition, it reduces
tion and lifetime of the materials.
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.
Material data for SIGRAFINE® MTN extruded graphite
Typical application: degassing systems
Typical properties
Bulk density
Max. particle size
Open porosity
Standard dimensions of MTN
Units
Ø 50/12 x 3000 mm
g /cm³
1.62
mm
0.4
24
Vol. %
Dynamic modulus of elasticity
GPa
II
12
Flexural strength (4 pt)
MPa
II
18
Compressive strength
MPa
II
25
25
MPa
II
10
10 -⁶K-¹
II
0.8
0.5
II
160
Tensile strength
Thermal expansion (20 – 200 °C)
Coefficient of permeability (20 °C)
Thermal conductivity (20 °C)
–I
cm²/s
Wm-¹K-¹
Ash content
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.
%
0.15
18
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.
sgl group – the carbon company
19
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
b Quality testing of a
SIGRAFINE strip die
We have wide-ranging expertise in raw materials,
We use this broad base to offer our customers the
advanced manufacturing processes, and long­
best solutions possible. That's how we live up to our
standing application and engineering know-how.
claim: Broad Base. Best Solutions. This claim is also
We have a comprehensive portfolio of carbon,
upheld by our corporate SGL Excellence philosophy
graphite, and carbon fiber products and our
of continuous improvement.
integrated value chain covers everything from
carbon fiber to composites. With a global sales and
distribution network and modern production sites
in Europe, North America, and Asia, we are close to
our customers throughout the world.
+ More information can be found by visiting:
www.sglgroup.com
sglgroup
sglgroup
Contact
europE/Middle East/Africa
SGL CARBON GmbH
Drachenburgstrasse 1
53170 Bonn/Germany
gms-europe@sglgroup.com
americas
SGL CARBON LLC
900 Theresia Street
PA 15857 St. Marys/USA
gms-americas@sglgroup.com
asiA/pacific
SGL CARBON Far East Ltd.
12 Fl, Shanghai Oriental Plaza
31 Wujiang Road
Shanghai 200041/PR China
gms-asia@sglgroup.com
Picture credits:
Allgemeine Gold- und Silberscheideanstalt AG, Pforzheim/Germany (page 6)
SM Sächsisches Metallwerk Freiberg GmbH, Freiberg/Germany (page 9)
® registered trademarks of SGL CARBON SE
07 2015/0 2NÄ Printed in Germany
This 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 products 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 & Systems
SGL CARBON GmbH
Soehnleinstrasse 8 | 65201 Wiesbaden/Germany
www.sglgroup.com/gms