Graphite Materials and Systems. Specialty Graphites for the Metal Industry

Transcription

1 Graphite Materials and Systems Specialty Graphites for the Metal Industry

2 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.

3 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 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, vibrationmolded, 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, b Boring a crucible made from SIGRAFINE fine-grain graphite 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, commissioning, 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.

4 4 Specialty graphites made by SGL Group. Solutions for the metal industry. For our customers in the metal industry, everything revolves around melting, casting, and shaping at very high temperatures. With the increasing demands on material purity, product lifetime, and cost efficiency, the requirements for components and systems are becoming ever more challenging. The 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)

5 SPECIALTy GRAPHITE solutions FOR THE METAL INDUSTRY 5 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 requirements 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 inspections and raw materials testing to continuous monitoring of process parameters and sampling from each individual block that leaves the production process. In addition, clear identification codes make it possible to trace the provenance of each product every step of the way. + Video: isostatic graphite, a key product for the high-tech industry. sglgroup Graphite crucible Spout Cooling system Graphite die Graphite gas injection tube 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 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

7 SPECIALTy GRAPHITEs FOR CONTINUOUS CASTING 7 SIGRAFINE fine-grain graphites for dies and crucibles Continuous casting of non-ferrous metals, precious metals, and iron is a widely used process. It offers non-stop production 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 throughput, 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 carburizing 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. 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 R4340 R4500 R4550 R4810 R4820 round CuZn strip wire CuSn CuNiZn CuNi Ag alloys Au alloys round strip wire round strip wire round strip wire round strip wire 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.

8 8 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 processing of the raw material or by the degree of graphitization. Typical thermal conductivity of graphite Typical thermal expansion of graphite Thermal conductivity [%] Thermal expansion 1) 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 Bulk density g /cm³ Open porosity Vol. % Average pore size µm Coefficient of permeability (20 C) cm²/s Rockwell hardness HR ₁₀ / ₁₀₀ 80 HR ₅ / ₁₀₀ 70 HR ₅ / ₁₀₀ 90 HR ₁₀ / ₁₀₀ 95 HR ₁₀ / ₁₀₀ 100 Flexural strength MPa Compressive strength MPa Dynamic modulus of elasticity GPa Thermal conductivity (20 C) Wm - ¹K - ¹ Thermal expansion ( C) 10 - ⁶K - ¹ Ash content % Standard dimensions of SIGRAFINE isostatic graphites for continuous casting R4340 R4500 R4550 R4810 R 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 x 1230 mm Ø 380 x 520 mm Other grades and dimensions on request. Please contact us. You will find the US-units in the data sheet enclosed with the brochure.

9 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 advan tages 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 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

11 SPECIALTy GRAPHITEs FOR DIE CASTING AND SINTERING 11 SIGRAFINE fine-grain graphites for molds Railroad wheels and diamond drill bits are typical die-cast and sintered products. Our carbons and extruded, vibrationmolded, 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. 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 vibration-molded and die-molded graphites. These materials, sold under the brand name SIGRAFINE, are primarily character 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. For components used to produce diamond drill bits, we supply 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. b SIGRAFINE graphite molds for pressure sintering

12 12 Unlike with most materials, the tensile, compressive, and flexural strength values of graphites increase with rising temperature 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 temperaturedependent specific heat value. Mechanical strength of graphite Specific heat of graphite Mechanical strength [%] Specific heat [J/gK] Temperature [K] Temperature [K] Material data for SIGRAFINE HMR die-molded graphite Typical application: molds for railroad wheels Typical properties 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. Units Standard dimensions of HMR Ø 1090 x 585 mm Ø 1220 x 585 mm Ø 1395 x 585 mm Bulk density g /cm³ 1.65 Max. particle size mm 0.8 Flexural strength (3 pt) MPa II 16.9 Thermal conductivity (20 C) Wm - ¹K - ¹ II 116 Thermal expansion ( C) 10 - ⁶K - ¹ II 3.61 Rockwell hardness II 23 Ash content % < 0.1 Iron content ppm < 200

13 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 Standard dimensions of MKUN Standard dimensions of HLM Ø x 1000 mm Ø x 600 mm Ø 1685 x 550 mm 610 x 720 x 2700 mm Ø x 1830 mm 500 x 500 x 3300 mm 600 x 600 x 3300 mm Typical properties Units 630 x 1300 x 1420 mm Bulk density g /cm³ Max. particle size mm 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 I Tensile strength MPa II I Thermal expansion ( C) 10 - ⁶K - 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. II I

14 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.

15 SPECIALTy GRAPHITEs FOR DEGASSING SYSTEMS 15 SIGRAFINE fine-grain graphites for degassing systems and casting rings Graphite offers considerable advantages over other materials 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 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

17 SPECIALTy GRAPHITEs FOR DEGASSING SYSTEMS 17 Oxidation rates of gas injection tubes Effective surface of the flushing gas 30 6 Relative oxidation rate unprotected oxidation-protected Temperature [K] Contact surface/liter gas [m2] Gas bubble diameter [mm] 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 protection and lifetime of the materials. 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. Material data for SIGRAFINE MTN extruded graphite Typical application: degassing systems Typical properties Units Standard dimensions of MTN Ø 50/12 x 3000 mm Bulk density g /cm³ 1.62 Max. particle size mm 0.4 Open porosity Vol. % 24 Dynamic modulus of elasticity GPa II 12 Flexural strength (4 pt) MPa II 18 Compressive strength MPa II 25 I 25 Tensile strength MPa II 10 Thermal expansion ( C) 10 - ⁶K - ¹ II 0.8 Coefficient of permeability (20 C) cm²/s 0.5 Thermal conductivity (20 C) Wm - ¹K - ¹ II 160 Ash 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.

18 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.

19 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, advanced manufacturing processes, and longstanding application and engineering know-how. We have a comprehensive portfolio of carbon, graphite, and carbon fiber products and our 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. We use this broad base to offer our customers the best 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: sglgroup sglgroup

20 Contact europe/middle East/Africa SGL CARBON GmbH Drachenburgstrasse Bonn/Germany gms-europe@sglgroup.com americas SGL CARBON LLC 900 Theresia Street PA St. Marys/USA gms-americas@sglgroup.com asia/pacific SGL CARBON Far East Ltd. 12 Fl, Shanghai Oriental Plaza 31 Wujiang Road Shanghai /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 /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 Wiesbaden/Germany