5xxx aluminum alloy capable of refining mig weld grains and preparation method and application thereof

A preparation method of a 5XXX aluminum alloy capable of refining MIG weld grains, wherein the 5XXX aluminum alloy comprises the following compositions in percentage by weight:

• 4.0-4.9% of Mg, 0.2-0.5% of Mn, 0.01-0.06% of Ti, 0.1-0.35% of Fe, less than 0.05% of B, and the balance of Al and inevitable impurities, the content of each inevitable impurity is less than 0.05%, and the total content of the impurities is less than 0.15%;
• and the preparation method comprises the following steps:
• step S1, subjecting raw materials of a 5XXX aluminum alloy to casting to obtain an ingot, wherein the Ti is added through an Al-5Ti-1B intermediate alloy at 750-770° C.;
• step S2, subjecting the ingot to homogenization treatment at a temperature of 500-520° C. for 3-5 h to obtain a homogenized ingot;
• step S3, subjecting the homogenized ingot to hot rolling to obtain a hot rolled sheet;
• step S4, subjecting the hot rolled sheet to cold rolling to obtain a cold rolled sheet;
• and
• step S5, subjecting the cold rolled sheet to annealing treatment to obtain the 5XXX aluminum alloy capable of refining MIG weld grains.