Low-Sc Al-Mg-Sc-Zr alloy sheet and preparation method thereof

The invention discloses a low-Sc Al-Mg-Sc-Zr alloy sheet and a preparation method thereof, relates to an Sc-containing Al-Mg alloy sheet and a preparation method thereof and aims at solving the technical problems of high raw material price and poor mechanical property of the existing Sc-containing Al-Mg alloy. The alloy sheet is composed of Mg, Mn, Sc, Zr, Ti, Be, Si, Fe and the balance of impurities and Al. The method comprises the steps of firstly, proportioning; secondly, smelting; thirdly, casting; fourthly, homogenizing annealing; fifthly, hot rolling; sixthly, saw cutting to obtain a finished product. The alloy sheet disclosed by the invention has the normal-temperature and low-temperature mechanical property, damage tolerance as well as excellent welding performance and corrosion resistance of a common Al-Mg-SC alloy sheet, and also has the advantage of lower raw material cost. The preparation method is used for preparing the low-Sc Al-Mg-Sc-Zr alloy sheet.