For Steel Base Flange For Square Tubing, the three elements of solution treatment are temperature, holding time, and cooling rate. The solid solution temperature is mainly determined according to the chemical composition. Generally speaking, the solid solution temperature should be correspondingly high for the grades with many kinds of alloying elements and high content. Especially steels with high manganese, molybdenum, nickel, and silicon content can only be softened by dissolving them at a high solid solution temperature.
However, for stabilized steel, such as 1Cr18Ni9Ti, when the solid solution temperature is high, the carbide of the stabilizing element is dissolved in austenite and will precipitate in the grain boundary in the form of Cr23C6 during subsequent cooling, causing intergranular corrosion. In order to prevent the carbides (TiC and NbC) of the stabilizing elements from decomposing or entering into solid solution, the lower limit solid solution temperature is generally used.
