This paper deals with the influence of steel composition (with respect to the microalloying elements) and therrnomechanical treatment on structure and mechanical behaviour of HSLA (High Strength Low Alloy) steels. Four different microalloyed steels have been TM rolled under variing conditions. The austenite structure prior to transformation could be revealed by means of a special etching techni...

This paper reports on the precipitation behaviour and microstructural evolution in ~20% cold rolled NbMoV and V single microalloyed low carbon steels during intercritical annealing. The microstructure and precipitation behaviour were studied by optical and scanning/transmission electron microscopy and microanalysis, X-ray diffraction technique and Vickers hardness testing. After intercritical a...

Microalloyed steels have a maximum of 2% in alloying elements and are used the automotive petrochemical industries. The microstructure mechanical properties these depend on chemical composition, processing addition molybdenum, niobium, titanium vanadium. To evaluate molybdenum effect properties, two microalloyed steels, with similar levels vanadium, were prepared forged. 0.056 0.160 percent by ...

low carbon steel samples were both shot into and inoculated with titanium in order to improve mechanical properties such as strength and toughness. sem observations and x-ray analyses revealed that titanium nitride and titanium carbonitride precipitates being scattered in the ferrite substrate reduce the grain size in all as-cast, heat-treated and as-rolled cases. the growth of the grains at hi...

Small angle neutron scattering (SANS) was used to quantify the precipitate characteristics (i.e., mean precipitate size, number of precipitates, and distribution broadening) in X-70 and X-80 pipeline steel and in grades 80 and 100 microalloyed steel plate. The precipitate distributions measured for the different steels were correlated with the finish rolling temperature (FRT) and cooling interr...

The relationship between microstructure and tensile properties of an Nb–Ti microalloyed X90 pipeline steel was studied as a function of finish rolling temperature using a Gleeble 3500 simulator, an optical and scanning electron microscope, electron back scattered diffraction (EBSD), a transmission electron microscope (TEM) and X-ray diffraction. The results indicate that the microstructure is p...

Toughness is a complex material characteristic that is viewed from multiple aspects and is influenced by numerous factors. It is very important to have ability to assess toughness, i.e. to determine ductile or brittle material behaviour at any specific time. Beside total impact energy obtained at Charpy instrumented pendulum, the use of additional parameters such as lateral extension measuremen...