Protective gas and protective method for smelting magnesium and magnesium alloy

technical field [0001] The invention belongs to the metallurgical technology, and mainly relates to a protective gas for smelting magnesium and magnesium alloys and a protective method. Background technique [0002] Magnesium alloys are called "new metal materials after the 1990s". The development and application of magnesium alloys are of great significance to human beings. Because the molten magnesium alloy is easy to oxidize rapidly in the atmosphere, and the oxide film on the surface of the magnesium alloy cannot prevent the further oxidation of the melt and cause it to burn. Therefore, the oxidation prevention and flame retardancy of magnesium and magnesium alloys become particularly important in the process of smelting and casting. At present, there are three main flame retardant methods for magnesium alloys in the smelting process: alloy element method, flux protection method and gas protection method. Due to the need to select specific alloying elements, the alloy ...