Quality standard of spheroidizing agent
According to the reaction thermodynamics and kinetics of the spheroidized elements in molten iron, the factors influencing the quality of the spheroidizing agent in the production process and the factors influencing the use process of the foundry, the standards for judging the quality of the spheroidizing agent are put forward as follows:
(1) Affinity of spheroidized elements with sulfur, oxygen and other elements in molten iron. It has a strong affinity, and forms compounds with it, which act as the foreign core in the solidification process of molten iron, such as rare earth, magnesium, calcium and other spheroidized elements.
(2) the ability of spheroidizing elements to change the morphology of graphite from flaky to spherical.
(3) The density and boiling point of the spheroidizer are lower than that of liquid iron. Small density can automatically float in molten iron, the boiling point is lower than the temperature of molten iron treatment, magnesium can be converted into a gaseous state at the temperature of the treatment, there is a self-stirring effect, so as to improve the effect of spheroidization.
(4) the content of magnesium oxide in the spheroidizer is equal to about 10% of the content of magnesium.
(5) nodulating agent compact, no segregation, no shrinkage porosity, no powder.
(6) the particle size distribution of the spheroidizer is uniform, no powdery alloy, obtuse Angle multi-deformation particles is better.
(7) The above conditions basically cover the quality requirements in the production and use of nodulating agent, so it can be used as a unified quality standard for the supply and demand parties.
As a kind of additive widely used in cast iron industry, the quality and performance of spheroidizing agent are very important. Therefore, on the basis of choosing high-quality products, the spheroidizing agent is added and used in accordance with the instructions to achieve the best use effect.
