Microalloyed steel

About: Microalloyed steel is a research topic. Over the lifetime, 2183 publications have been published within this topic receiving 33586 citations.

Effect of Mg Addition on the Characterization of γ-α Phase Transformation During Continuous Cooling in Low Carbon Steel

Abstract: The influence of magnesium on the phase transformation and mechanical properties has been investigated by means of dilatometric and microstructural analysis in low carbon microalloyed steel. The thermal simulation experiments were performed on a Gleeble-3800 system equipped with a high-speed deformation dilatometer. The results reveal that, by adding with Mg, the pearlite transformation is delayed, and the pearlite has a scattered distribution even at low cooling rates from 0.1 to 0.5 K/s. It also shows that Mg tends to promote the bainite transformation as a result of the formation of acicular ferrite and granular bainite. Acicular ferrite is attributed to the change of dominant oxide inclusions from inert Al2O3, to xMgO · Al2O3, which serves as an effective nucleant for acicular ferrite. Moreover, bainitic structure obtained by the addition of Mg into the molten steel exhibits the remarkable improvement of toughness and tensile properties.

Effects of chromium on the microstructure and hot ductility of Nb-microalloyed steel

Abstract: It is well-known that the surface quality of the niobium microalloy profiled billet directly affects the comprehensive mechanical properties of the H-beam. The effects of chromium on the γ/α phase transformation and high-temperature mechanical properties of Nb-microalloyed steel were studied by Gleeble tensile and high-temperature in-situ observation experiments. Results indicated that the starting temperature of the γ→α phase transformation decreases with increasing Cr content. The hot ductility of Nb-microalloyed steel is improved by adding 0.12wt% Cr. Chromium atoms inhibit the diffusion of carbon atoms, which reduces the thickness of grain boundary ferrite. The number fractions of high-angle grain boundaries increase with increasing chromium content. In particular, the proportion is up to 48.7% when the Cr content is 0.12wt%. The high-angle grain boundaries hinder the crack propagation and improve the ductility of Nb-microalloyed steel.

Influence of Heat Treatment on the Corrosion of Microalloyed Steel in Sodium Chloride Solution

Abstract: Microalloyed Steels find wide application in car bodies and other engineering parts because of its high strength as well as high ductility. Very fine grained microstructure is the reason behind the combination of strength and ductility. It has been reported that repeated quenching leads to further refining of microstructure. In the present investigation, corrosion resistance property of E34 microalloy steel has been studied in 3.5% NaCl solution in different microstructural conditions such as the as rolled one and three repeated quenched conditions. Weight loss, potentiodynamic polarization method, and electrochemical impedance spectroscopy (EIS) techniques have been used. To reveal the corrosion resistance of different treated steels, some significant characterization parameters such as , , , and in linear polarization and EIS curves were analyzed and compared. It is found that with repeated recrystallization grains become finer, and corrosion rate increases suggesting that a compromise has to strike between high mechanical property and corrosion rate.

Kinetics of bainite-to-austenite transformationduring continuous reheating in low carbon microalloyed steel

Abstract: 膨胀计被用来在连续再热过程期间与 bainite 的起始的微观结构在低碳 microalloyed 钢学习 bainite-to-austenite 转变的动力学。bainite-to-austenite 转变被观察以低加热的率发生在二个步骤。第一个步骤是 bainite 的溶解，并且第二是一个溶解过程控制的留下的 bainite-to-austenite 转变。二个步骤在低加热由散开发生的表演评估的奥氏体形成的动力学的计算结果。然而，在高加热率， bainite-to-austenite 转变发生在一个单个步骤，和这个过程主要被统治由砍。奥氏体的生长率在大约 835 点到达最大值 ? 畦吗？

Development of {111} texture during cold rolling and recrystallization of a CMnV dual-phase steel

Abstract: Four different dual-phase structures were produced in a vanadium microalloyed steel by air cooling and water quenching from the austenitizing temperature (910°C) and then intercritically annealing at 750 and 810°C, followed by a final water quenching. Steels with different distributions of ferrite and martensite were deformed 60% by cold rolling and subsequently recrystallized at 650 and 800°C. Texture measurements, using the conventional pole figure technique and also the orientation distribution function methods, were carried out on the cold-rolled as well as the recrystallized materials. Reasonably strong {111} fibre texture are observed for the cold-rolled materials. Recrystallization textures which are similar to the deformation textures also show a strong {111} fibre, particularly for the material recrystallized at 800°C. Differences between the intensities of the {111} texture produced by the 800 and 650°C anneals are reflected in the corresponding r values which are generally poor in this alloy. The sharper intensity of the {111} texture in the material recrystallized in the intercritical temperature range has been explained as due to selective consumption of grains other than {111} during the α → γ transformation.