Comtes Fht | Date: 2017-04-19
This heat treatment of bearing steel comprises annealing and hardening. Hardening is carried out after annealing and after the manufacture of structural parts from this steel. The first part of the annealing process is heating of the steel at a rate of more than 1 C/s to a temperature in the range between 750 C and 900 C. It is followed by holding at the temperature achieved for at least 400 seconds. This is followed by cooling at a rate higher than 0.02 C/s to a temperature, at which austenite begins to transform to ferrite and carbides. In the next step, there is cooling to such temperature and at such rate that complete transformation of austenite to ferrite and carbides takes place at least in the desired location of the steel. The cycle of heating, holding and cooling is carried out at least once. Then the steel is cooled to the ambient temperature. In the preferred embodiment, the quenching temperature during subsequent hardening is lower than the quenching temperature of the conventionally annealed steel in question. The steel may be heated by induction.
Comtes Fht | Date: 2014-12-30
The gear driven by wobble movement contains an ergonomic pendulum (D), a centric disk (C) and a flywheel (A) which have a common axis (S) of rotation. In the axis (S) of rotation a shaft (H) is placed which is rigidly joined to the pendulum (D). The mutual concentric position of the centric disk (C) and the flywheel (A) is delimitated by one planet disk (B) at least which contacts the outer periphery of the centric disk (C) and the internal periphery of the flywheel (A) and is joined rotatably to the supporting structure (T). The supporting structure (T) is fixed to the linked structure which fixes the supporting structure (T), together with the planet disk (B), against rotation with respect to the axis (S) of rotation. Between the shaft (H) and the flywheel (A) a first freewheel (VI) is situated while between the shaft (H) and the centric disk (C) a second freewheel (V2) is situated. The senses of rotation of the freewheels (VI and V2) are different. The vehicle comprising this gear has a linked structure to which the supporting structure (T) is fastened, having the form of the frame (U). To it the wheel (K) or the pair of wheels (K) are fastened.
Matplus Gmbh and Comtes Fht | Date: 2015-03-24
The invention concerns a component made of a steel alloy comprising iron and as alloying element copper, in particular consisting of (in wt % in relation to the total alloy, wherein the sum of all constituents equals 100 wt %) iron96, carbon 0.04 to 0.12, copper 0.5 to 2.0, manganese+silicon+chromium+nickel 0.5 to 2.5, titanium 0 to 0.1, boron 0 to 0.005, and typical unavoidable impurities. In the production of semi-finished goods and of components, a combination of cold working and annealing treatment below the recrystallization temperature is used in order to thus obtain advantageous properties with regard to strength and ductility.
Matplus GmbH and Comtes Fht | Date: 2017-02-01
The invention relates to a component made of a steel alloy comprising iron and, as an alloying element, copper, in particular consisting (in wt% in relation to the total alloy, wherein the sum of all constituents equals 100 wt%) of iron 96, carbon 0.04 to 0.12, copper 0.5 to 2.0, manganese + silicon + chromium + nickel 0.5 to 2.5, titanium 0 to 0.1, boron 0 to 0.005, and typical unavoidable impurities. In the production of semi-finished products and of components, a combination of cold-working and annealing treatment below the recrystallization temperature is used in order to thus obtain advantageous properties with regard to strength and ductility.
Slama P.,Comtes Fht |
Nachazel J.,Comtes Fht
IOP Conference Series: Materials Science and Engineering | Year: 2017
Aluminium Al-Mg-Si-type alloys (6xxx-series) exhibit good mechanical properties, formability, weldability and good corrosion resistance in various environments. They often find use in automotive industry and other applications. Some alloys, however, particularly those with higher copper levels, show increased susceptibility to intergranular corrosion. Intergranular corrosion (IGC) is typically related to the formation of microgalvanic cells between cathodic, more noble phases and depleted (precipitate-free) zones along grain boundaries. It is encountered mainly in AlMgSi alloys containing Cu, where it is thought to be related to the formation Q-phase precipitates (Al4Mg8Si7Cu2) along grain boundaries. The present paper describes the effects of mechanical working (extrusion, drawing and straightening) and artificial aging on intergranular corrosion in rods of the 6064 alloy. The resistance to intergranular corrosion was mapped using corrosion tests according to EN ISO 11846, method B. Corrosion tests showed dependence of corrosion type on mechanical processing of the material. Intergranular, pitting and transgranular corrosion was observed. Artificial ageing influenced mainly the depth of the corrosion. © Published under licence by IOP Publishing Ltd.
Chvostova E.,Comtes Fht |
Dzugan J.,Comtes Fht
IOP Conference Series: Materials Science and Engineering | Year: 2017
Application of the mini samples methods is very common especially for residual service life assessment of the components operating in the energy sector. Residual lifetime of operating device can be evaluated using standard tests, but these usually cannot be performed due to limited material amount that can be extracted from the components. It is possible to use in these cases a semi destructive sampling of materials and testing methods employing miniature specimens. This article deals with comparison of the creep results obtained with the use of on standard test bars and sub sized samples such as Small Punch Test and newly proposed miniature samples that are axially loaded. The experiment was performed on steam line steel CSN 15 128 after operation. Emphasis was put to practical use of the test results and therefore residual life was assessed with the use of standard and new mini specimens. The results obtained for standard and mini samples exhibit very good agreement without necessity of any correlation as in the case of SPT and thus much more straight forward approach can be applied even for "unknown materials". © Published under licence by IOP Publishing Ltd.
Kubina T.,Comtes Fht |
Nachazel J.,Comtes Fht
Materiali in Tehnologije | Year: 2017
The fabrication of laminated steel composites by hot rolling is described. Composite sandwiches were made from martensitic stainless tool steel with an increased nitrogen content and from standard AISI 304 steel using 3 to 7 layers. The maximum strength of the martensitic steel was 1370 MPa. The composite sheets had strengths in the range 950-1200 MPa, depending on the number of layers and the proportion of the steels. A metallographic observation of the fractures revealed that the first occurrence was fracture in the martensitic steel layers, followed by deformation of the layers of tough austenitic AISI 304 steel. The notch toughness values were the highest when the notch was oriented from the sheet surface to the sheet interior.
Podany P.,Comtes Fht |
Duchek M.,Comtes Fht
Materials Science and Technology Conference and Exhibition 2016, MS and T 2016 | Year: 2016
Forging -And its variant known as closed-die forging - is one of the oldest methods of processing metals. Although recent developments in materials science and metal physics led to improvements in various aspects of die forging technology (such as material utilization and wear resistance), the service life of industrial dies is still a matter of importance in the mass production of forgings. Large dies are an example of an application where repair must be carried out after the wear reaches some critical limit. This paper summarizes the most widely used techniques and options for repairing tools for closed-die forging. An example is given of one particular repair method where the use of the appropriate material led to a longer lifetime of the repaired die when compared to the one before repair. © 2016 MS and T16®.
Agency: European Commission | Branch: H2020 | Program: RIA | Phase: LCE-17-2015 | Award Amount: 9.63M | Year: 2016
The share of renewable energy is growing rapidly driven by the objective to reduce greenhouse gas emissions. The amount of electric power which can be supplied to the grid depends on the time of the day and weather conditions. A conventional fleet of thermal power plants is required to compensate for these fluctuations before large scale energy storage technologies will be mature and economically viable. All power market projections expect this to be the case for the next 50 years at least. For a strong expansion of renewables, this fleet has to operate flexibly at competitive cost. Current power plants cannot fill this role immediately without impeding their efficiency and engine lifetime through increased wear and damage induced by the higher number of (shorter) operating/loading cycles. New technologies need to be introduced to balance demand peaks with renewable output fluctuations at minimal fuel consumption and emissions without negative effects on cycling operation. The FLEXTURBINE partners have developed a medium to long term technology roadmap addressing future and existing power plants. The FLEXTURBINE project presented hereafter is the first step in such technology roadmap and consists of: (1) new solutions for extended operating ranges to predict and control flutter, (2) improved sealing and bearing designs to increase turbine lifetime and efficiency by reducing degradation/damages, and (3) an improved lifecycle management through better control and prediction of critical parts to improve competitive costs by more flexible service intervals and planned downtime, and by reducing unplanned outages. In all areas, individual technologies will be developed from TRL 3 to TRL 4-6. FLEXTURBINE brings together the main European turbine manufacturers, renowned research institutes and universities. It involves plant and transmission system operators to include user feedback and to prepare the take-up of the FLEXTURBINE technologies in power plants world-wide.
Hodek J.,Comtes Fht
METAL 2014 - 23rd International Conference on Metallurgy and Materials, Conference Proceedings | Year: 2014
Induction heating is today wide used technology in industry in huge range of fields. Solution of this process contains both solution of the electromagnetic field and solution of the thermal field. In the past were knowledge and experiences obtained mainly from experiments but at the present time is possible to study induction heating phenomena using modern numerical method especially the finite element method . The numerical solution helps to understand induction heating more complex and points out critical issues. Big advantage is use the numerical solution for induction heating coil design. This approach can avoid of long-lasting and expensive experiments with different variants. This paper deals with FEM simulations of induction heating. There are electromagnetic and thermal field taken into the account. The material properties are obtained on the base of material chemical composition. The numerical model considers thermal dependant material properties. Different coil design is considered and variants are compared.