Modelling of technological processes of heat treatment or welding, involving multiple heat source transitions, requires considering the phenomenon of tempering. In work have been presented results of dilatometric research of hardened C45 steel subjected to tempering. The analysis of the infl uence of heating rate at the kinetic determined from dilatometric curves has been made. There have also ...

In this paper, the microstructural damage evolution of a steel with ferrite–pearlite microstructure (C45E) was investigated during process cold upsetting. The development and accumulation were analyzed in different areas samples that deformed at strain levels. scanning electron microscopy (SEM) results showed various mechanisms nucleation microcavities occurred upsetting process. quantitative t...

sunflower is one of the most important edible oil that growth of annual crops, it is grown over a widely area and is considered a crop adapted to an every environmental conditions, in order to study growth analysis of sunflower under sowing date and cultivars in dry condition a farm experiment was conducted a split plot arranged in a complete randomized block design with three replications in t...

non-destructive eddy current (ec) technique has long been used to detect discontinuities in materials. recently, its application has been extended to characterize materials microstructure. in order to identify different microstructures, four plain carbon steel bars with different chemical compositions (aisi 1015, 1035, 1045 and 1080) were used in annealed condition. the pearlite percentage, car...

In this paper, we present results of fatigue tests a natural steel composite material for cyclic bending by zero-loading cycle. Natural ferrite-martensitic (NFMC) has structure alternating layers ductile ferrite and strong martensite, which causes special mechanism crack retardation under loading. The cycle assumes the presence tensile forces directed only in one direction, makes it possible to...

The response of a strong bainitic–steel to tempering at high temperatures is investigated, because a softened state is sometimes necessary during the manufacture of engineering components, prior to the final heat–treatment which hardens the material. Thermodynamic calculations conducted to determine the maximum temperature at which the steel could be annealed without forming austenite were foun...

An extremely fine, fully pearlitic structure with an interlamellar spacing 30–50 nm has been obtained during continuous cooling transformation at a rate as low as 0.1 C s, of the steel that is normally used to produce nanostructured bainite. The solutes cobalt and aluminium have been added to accelerate the rate of reaction and reduce the interlamellar spacing by increasing the free energy of t...

Abstract This work presents a multi-scale modelling framework for thermo-mechanical behaviour of Compacted Graphite Iron cast iron. A general thermo-elasto-visco-plastic model is developed to describe the matrix (pearlite) behavior under cyclic loading, which parameters are identified from tests on pearlitic steel. The pearlite takes into account temperature dependent rate-dependency and kinema...