Method for improving fatigue crack propagation resistance of Al-Zn-Mg alloy extrusion material

The invention relates to an Al-Zn-Mg alloy extruded profile, in particular to a method for improving the fatigue crack propagation resistance of the Al-Zn-Mg alloy extruded profile. The method comprises the following steps: carrying out multi-stage homogenizing annealing treatment on an Al-Zn-Mg alloy cast ingot, and then carrying out hot extrusion on the cast ingot subjected to the homogenizing annealing treatment to obtain an Al-Zn-Mg alloy hot extrusion profile; then the Al-Zn-Mg alloy hot extrusion profile is sequentially subjected to solution treatment and artificial aging treatment; the content of V in the Al-Zn-Mg alloy ranges from 0.05% to 0.1% in percentage by mass. According to the method for improving the fatigue crack propagation resistance of the Al-Zn-Mg alloy extrusion material by adding V, the service life of the Al-Zn-Mg alloy extrusion material is further prolonged through component design and process optimization. 本发明涉及Al-Zn-Mg合金挤压型材，具体涉及提高Al-Zn-Mg合金挤压材抗疲劳裂纹扩展性能的方法。所述方法包括：将Al-Zn-Mg合金铸锭进行多级均