Open Access Conference Proceedings

Abstract: Nickel-chromium alloys are increasingly used in constructions of the most loaded machine components including aircraft engines. Therefore, determining the parameters of metal forming for those alloys is very important. [..] Read more

Abstract: The present paper approaches the topic from two perspectives. The first one is a mathematical approach, using which various experimental designs will be compared. [..] Read more

Abstract: Metal forming processes are continually being modified and enhanced in order to obtain products with improved functional properties and to gain new production opportunities and economical benefits. Novel incremental bulk metal forming techniques provide the potential to achieve both these goals. [..] Read more

Abstract: Intensity of structural changes during forging is usually determined in dependence on the forging ratio. Forging ratio at elongation is most often calculated with use of simple relations, which are based on the change of crosssection of the forged pieces. [..] Read more

Abstract: The paper presents experimental results of diameter reduction in tubes with the angle of flare α=300. Tube diameter reduction was performed on the WPM-120 cold profile eccentric rolling machine. [..] Read more

Abstract: In the paper the analysis of the gas turbine forging process made from highly alloyed steel NiCrMoV to power engineering application was done. Numerical analysis of material flow in following stages of forging process also effective strain distribution in forging was introduced. [..] Read more

Abstract: This article is devoted to the problem of forming of axisymmetric elements of hard-to-deform material. The first stage was the deep drawing process of metal discs. [..] Read more

Abstract: This paper summarizes the most important results of research dealing with the use of the magnetic spot-pole method and measurement of ultrasonic wave velocity for process control of castings made from austempered ductile, grey and vermicular-graphite irons. It describes the most important dependencies between the measured physical quantities on the specific structure of these materials, especially the content of retained austenite. [..] Read more

Abstract: Ferritic-martensitic P91 grade steel is widely used for manufacture pipes and boilers of thermal and nuclear power plants due to its high strength and creep behaviour at high temperatures and the advantage of small thermal stress in cyclic operations. During long-term operation of power plant components under elevated temperatures and steam pressure the changes of steels structure occur, on which those mechanical features and remnant service life depend. [..] Read more

Abstract: The work deals with hydrogen susceptibility of joint of explosively welded anticorrosion steel of 18Cr/10Ni type with titanium of commercial purity. Studied welds were after twice heat treatment (600°C/1.5 h/air) and those were tested in corrosive solution in accord with NACE Standard TM0177-2003 (sulphide stress cracking under stress), representing dynamic test. [..] Read more

Abstract: The formation of austenite above A1 temperature plays very important role in the heat treatment of hypo-eutectoid steels, especially automotive DP steels. It is widely accepted that the formation of austenite during intercritical annealing takes place in three stages: 1 – very rapid pearlite to austenite transformation, 2 – slower growth of austenite into ferrite, 3 – slow final equilibrium of ferrite and austenite. [..] Read more

Abstract: The paper presents the models of temperature field, phase transformation kinetics, the calculation of thermal and structural strains in a steel element during multi-pass Gas Metal Arc Weld surfacing. The temperature field is described analytically assuming a bimodal volumetric model of heat source and a semi-infinite body model of the surfaced (rebuilt) work-piece. [..] Read more

Abstract: The paper presents the calculations of temperature field, volume fractions of structural components and strains during multipass GMAW surfacing of a prismatic element made of S235 steel. The bimodal heat source model is used in the description of temperature field. [..] Read more

Abstract: In this paper is analyzed, through comparison, the cavitation erosion resistance of Duplex stainless steel, with a microstructure of approx. 50% austenite and 50% ferrite, solution annealed from 1060C with water cooling and finally nitrided at 520C for 40 hours in an ammonia environment. [..] Read more

Abstract: The macroscopic mechanical properties of steel are highly dependent upon microstructure, crystallographic orientation of grains and distribution of each phase present etc. Nanomechanical testing using depth sensing indentation (DSI) provides a straightforward solution for quantitatively characterizing each of phases in microstructure because it is very powerful technique for characterization of materials in small volumes. [..] Read more

Abstract: Austempered ductile cast iron is part of a family of heat-treated cast irons. Isothermal hardening transforms ductile cast iron into ausferritic cast iron (ADI), which has the appropriate characteristics of strength, the impact strength and fatigue resistance. [..] Read more

Abstract: Steel is the most popular structural material. The properties and practical applications of all constructional materials, including steel, are determined mostly by their structure. [..] Read more

Abstract: Managing instrumentation and control obsolescence, improving the safety, and extending the lifetime of older nuclear reactors (such as VVER-440) are the primary objectives of nuclear power plants in Central and Eastern Europe. Extending reactor life to 60 years and beyond will likely increase susceptibility and severity of known forms of degradation. [..] Read more

Abstract: Formed parts of the car-body represent cyclic loaded products. For the proper design of these parts is very important not only knowledge of deformation and stress material behavior at production by forming technologies but important is also knowledge of other factors which influence subsequent product utility properties at the car operation. [..] Read more

Abstract: The process of dynamic strengthening of Hadfield steel, currently widely used for cast railway frogs, was studied. Continual dislocation hardening up to the depletion of plasticity and creation of surface microcracks presents the specific limited state under rolling contact in this application. [..] Read more