Investigations were conducted on low-carbon steel and the steel with same chemical composition with addition of microalloying element niobium. While tensile testing was carried out, the thermographic measurement was tacking place simultaneously. A specific behavior of niobium microalloyed steel was noticed. Test results have shown that, in the elastic deformation region, thermoelastic effect oc...

This paper presents a study of the quasi-static and dynamic deformation behaviors of conventional and microalloyed medium-carbon steels in a wide temperature range. As strain rate increased, the flow stress increased at room temperature, but occasionally did not at elevated temperatures. The flow stress of the microalloyed steel containing precipitates was less sensitive to strain rate at room ...

Machining through turning was carried out in a lathe to study the chip formation of Multiphase Ferrite (F-B-M) microalloyed steel. Taguchi orthogonal array was employed to perform the machining. Continuous and discontinuous chips were formed for different cutting parameters like speed, feed and depth of cut. Optical and scanning electron microscope was employed to identify the chip morphology. ...

The resistance to hydrogen embrittlement is of essential importance for steels for vessels for storage of hydrocarbons and depends on the effect of absorbed hydrogen on steel ductility. API tests have shown for the 490 MPa yield stress HSLA steels with the microstructure of ferrite and cementite particles a much greater reduction of area than for the 350 MPa steel with the microstructure of pol...

fatigue behavior of a vanadium microalloy steel has been studied in this research. here, microstructure constituents were considered which essentially are dependent on the heat treatment conditions. the results of high cycle fatigue tests revealed that heat treatment procedure and cooling rates have significant effects on fatigue properties. optimal heat treatment cycle of the microalloyed stee...

Recently, the grain boundary−intragranular nucleation of ferrite has received great attention seeking for the improvement of the toughness in the steel, specially when conventional austenite grain refinement techniques are not enough. This paper deals with some relevant aspects about the competitive process of allotriomorphic and idiomorphic ferrite transformations in a medium carbon vanadium-t...

S. Rešković, I. Jandrlić, University of Zagreb, Faculty of Metallurgy, Sisak, Croatia, F. Vodopivec Institute of Metals and Technology, Ljubljana, Slovenia Using thermal imaging camera during tensile testing of low carbon and Nb microalloyed steel influence of testing rate on start of plastic deformation was investigated. The results showed that the onset of plastic flow is significantly differ...

The formation of precipitates, especially along austenite grain boundaries, greatly affects the formation of transverse cracks on the surface of continuous-cast steel. The steel composition and cooling history influences the formation of precipitates, and the higher temperature and corresponding larger grain growth rate under oscillation marks or surface depressions also have an important effec...

Microstructures and Charpy impact properties have been examined in two microalloyed steels following heat treatments to simulate weld heat affected zone (HAZ) structures over a range of heat input conditions, characterised by the cooling time from 800 to 500 !C (Dt8/5). The base materials were low carbon structural steel plates microalloyed with vanadium and nitrogen (V–N) and niobium (Nb), res...

a low carbon al-killed ti-added steel was produced in mobarakeh steel complex in iran. mechanical properties and microstructural characterizations of steel in the as-cast, hot-rolled, cold-rolled and annealed conditions are presented. dilatometery tests were carried out to measure the finishing and annealing temperatures of steel. it was found that the addition of small amounts of ti increased ...