Sistemska tehnika FORGED PRODUCTS FOR ALUMINIUM INDUSTRY

Sistemska tehnika FORGED PRODUCTS FOR ALUMINIUM INDUSTRY

ST shells for continous strip casting Shells for continuous casting produced by Sistemska tehnika enable optimal casting speeds, maximal casted tonnage per campaign, minimal crack appearance, minimal crack progression and low, evenly distributed roughness of the casted material s surface. Our customers experience up to 25% increase in the tonnage of the casted material in comparison to their average supplier s mixed performance. This is achieved by using specially developed proprietary steel grade combined with our own heat treatment. All of the heat treatment equipment was developed, designed and produced in-house together with appropriate technology. The results show optimal characteristics of our shells such as high heat conductivity and resistance to thermal fatigue. Microstructure of shells for continuous casting is optimized during the production process. Final microstructure of shells consists of determined relation between tempered martensite and finely dispersed carbides. Steel grade for shells was developed by our experts, specifically for the needs of non-ferrous industry. Besides optimal content of chemical alloys it is also characterized by the lowest possible levels of trace elements. In addition to high cleanliness, steel is also homogenized, which further improves mechanical characteristics. We guarantee the same material properties from start to scrap diameter. Chemical composition of steel PO209: PO209 C Mn Cr Mo V Ni Max 0,25 0,40 2,00 0,20 0,20 Min 0,50 4,00 1,80 0,50 0,60

2 3 Mechanical properties: Hardness (HB): 380 420 Yield strength (MPa): 1150 Impact strength (J): avg. 55* Grain size (acc. ASTM E112): min. 7 Thermal conductivity (Wm-1K-1): 39 Thermal coefficient of 20 200 C 20 400 C 20 600 C linear expansion (10-6 C-1): 12,2 13,3 13,6 * KU2 specimen according to EN ISO 148-1

Flow chart representing the production of shells for continuous strip casting UHP / EAF 40 T VD VAD + LF INGOT PUNCHING FORGING CUTTUNG CUTTING ROUGH TURNING ULTRASONIC AND MAGNETIC CONTROL HARDENING QUENCHING TEMPERING HARDNESS CONTROL TURNING TURING GRINDING AND MT (EDDY CURRENT CONTROL) CINTROL) DIMENSION CONTROL HARDNESS CONTROL PACKAGING OR OVERSEAS PACKAGING

4 ULTRA CLEAN STEEL Nonmetallic inclusion in trace (acc. DIN 50602 met. K1 < 10) 5 Homogeneous microstructure: Tempered martensite and equally distributed fine carbides. JOMINY TEST HARDENABILITY (the Jominy end quench test) 60 50 40 30 20 10 0 0 Hardness [HRc] Depth [mm] 10 20 30 40 50 60 70

ST forged rolls for cold rolling mills Forged rolls for cold rolling of nonferrous alloys produced by Sistemska tehnika fulfill the customer s demands for increased productivity, high reliability, safety of operation, finer surface quality, higher rolling speeds, and more demanding rolled materials and thus positively influence TCO (Total Cost of Ownership). This is achieved by combining the best steel grades, stateof-the-art heat treatment, precise machining, multi-step inspection of each roll, and continuous investments in the development of new qualities. Our forged rolls withstand high area pressure and are characterized by highly uniform hardness of +/-0,5 HRC throughout the working barrel and a very homogenous microstructure. We guarantee that the minimum hardness drop throughout the hardened layer is up to max. 3%. Microstructure of induction hardened layer is low tempered martensite and small carbides Microstructure of induction hardened layer is low tempered martensite and small carbides

Optimal mechanical characteristics are achieved by using our proprietary heat treatment. Rolls are quenched and tempered to basic hardness and then surface hardened to achieve optimal working hardness. This is done by using our own bi-frequency induction technology and equipment, developed, designed and produced in-house. Dual induction frequency (50-100 Hz, 500-1000 Hz) is continuously variable. Therefore several case depths up to 60 mm are possible. To achieve the best mechanical characteristics also on roll necks, we use our own award winning 3-D induction hardening machine. Here also the induction frequency is manually adjustable (2.8 khz- 25 khz) with several possible case depths. Induction hardening is followed by cryogenic treatment. This is an additional step in the heat treatment hardening process. It completes the transformation of the steel s microstructure from austenite to the stronger and harder martensitic structure. The hardness of the steel increases along with increasing the percentage of martensite in the structure. Hence, wear resistance increases as it correlates positively with hardness. Wear resistance, in addition, depends on the presence of carbides. To ensure the highest quality possible, each roll is inspected six times throughout the production process. In addition, we measure levels of retained austenite and residual stresses to guarantee the highest reliability and safety of operation. For this operation we use an accurate and safe X-ray diffractometer for measuring residual stresses and retained austenite contents. Xstress measures the stresses on crystalline material by X-rays, based on the phenomenon known as Bragg s law. 6 7 With each shipment the customer receives the inspection certificates and the quality guarantee. Steel grades: Ravne brand name OTV1C OTV2C OTV1D OTV1B OTV2B Roll nomenclature 3 % Cr steel 3 % Cr steel 4 % Cr steel 5 % Cr steel 5 % Cr steel C 0,83 Si 0,85 0,85 Mn 0,6 0,6 0,4 0,3 0,3 Cr 3,0 3,0 4,0 5,0 5,0 Mo 0,5 0,5 0,5 0,53 0,5 V Comparison of main properties: Grade Wear resistance Hardening layer Max. Roll diameter Toughness OTV1C OTV2C OTV1D OTV1B OTV2B

ST forged rolls for foil Forged rolls for cold rolling of foil produced in Sistemska tehnika are suitable for the highest rolling speeds and loads. They fulfill the highest demands for surface quality and enable high quality and high speed rolling of foil, down to 6 microns. Microstructure of induction hardened layer is low tempered martensite and small carbides Microstructure of induction hardened layer is low tempered martensite and small carbides

Experts of Sistemska tehnika have, together with its steel producer, developed a special ESR technology for production of ultra clean steel grades, optimized for cold rolling of foil. Second refining, combined with our heat treatment technology gives optimal results in terms of: 8 9 - The cleanest steel on the market (DIN 50602 method K, K1<5), - Dense structure without porosity, higher cleanliness, homogenous structure and chemical analysis over the whole roll, - Uniform hardness on the whole working surface of the roll within the tolerance range of +/-0,5 HRC, - Minimum hardness drop throughout the hardened layer up to 3%, - Concentricity between the barrel and bearing seats in tolerance <=0,005 or if required <=0,002 mm. Steel grades: Ravne brand name OHV4 OHV5 OTV1C OTV2C Roll nomenclature 2 % Cr steel 2 % Cr steel 3 % Cr steel 3 % Cr steel WR. NR. 1.2327 1.2375 / / DIN 86CrMoV7 83CrMoV9 / / C 5 0,88 Si 4 2,10 0 4 0,85 0,85 Mn 0,304 0,35 0,60 0,60 Cr 5,0 1 9 2,1 3,0 3,0 Mo 0,525 0,325 0,5 0,5 V Comparison of main properties: Grade Wear resistance Hardening layer Max. Roll diameter Toughness OHV4 OHV5 OTV1C OTV2C

Quality from the beginning Tradition, experience, knowledge and quality assurance make us a reliable partner. Our strategic supplier and few additional international suppliers form a carefully selected and regularly checked procurement network. Complete technology support and cooperation We are here for you Sistemska tehnika is an ideal partner for a cooperation in the field of development, production and assembly of metallurgical equipment and components on the basis of your documentation. Efficient sales network Sistemska tehnika has developed an efficient sales network to give our customers full technical and commercial support when and where they need it: We think global, but act local. Excellent logistics Sistemska tehnika is located in the heart of Europe and is part of an international logistics group. This gives us an excellent international accessibility.

Sistemska tehnika d. o. o. Koro ka cesta 14, SI 2390 Ravne na Koro kem Slovenia Phone: +386 2 870 7606 Fax: +386 2 870 7605 Url: www.st-ravne.si/en E-mail: salesast-ravne.si 9/2015