Metal surface protection pre-processing process

[0034] A metal surface protection pretreatment process specifically comprises the following steps:

[0035] 1), first degrease the surface of the metal workpiece;

[0036] 2) Wash the metal workpiece twice with water after degreasing;

[0037] 3) The washed metal workpiece is polished with metallographic sandpaper;

[0038] 4) The polished metal workpiece is degreased again, and then washed for the third time;

[0039] 5) Apply silane solution to the workpiece washed three times;

[0040] 6) The workpiece coated with silane solution is blown dry with compressed air, and then cured at room temperature? time

[0041] 7) The cured workpiece is then painted,

[0042] Wherein, for the silane solution described in step 5), the components and weight per liter of the silane solution are:

[0043] Silane coupling agent KBM403 30g

[0044] Phytic acid 2g

[0045] Triethanolamine 6g

[0046] Sodium molybdate 0.2g

[0047] Sodium silicate 7g

[0048] Ethanol 100g

[0049] The bal