Method for treating and phosphatizing metal board without using acid

1. A method for treating and phosphatizing a metal board without using acid, comprising:

performing a degreasing step, wherein a degreasing agent is provided to remove grease and dirt from a surface of the metal board;

performing a blast-peening step by blasting and peening polygon blast-peening granules on the surface of the metal board through centrifugal impellers to remove an oxidized layer;

performing a washing step to wash the surface of the metal board, so as to remove powders generated from the blast-peening step;

performing a phosphatizing step to form a phosphate coating on the surface of the metal board, so as to provide protection;

performing another washing step to wash off remaining phosphatizing agents from the metal board;

performing a rustproofing step to apply a rustproofing agent on the metal board; and

performing a drying step to dry the metal board;

wherein a speed of blast-peening the granules in the blast-peening step is from 50 to 200 meters per second, a material of the blast-peening granules is carborundum or silicon carbide, and a diameter of the blast-peening granules is from 320 to 1400 μm.

2. The method according to claim 1 , wherein the blast-peening step includes providing a plurality of centrifugal impellers, the plurality of centrifugal impellers being arranged symmetrically at an upper surface and a lower surface of the metal board, respectively, and symmetrically performing blast-peening on the upper surface and the lower surface of the metal board.

3. The method according to claim 1 , wherein the blast-peening step includes adjusting distances between nozzles of the centrifugal impellers and the metal board.

4. The method according to claim 3 , further including providing a distance detector to detect the distances between the nozzles of the centrifugal impellers and the metal board.

5. The method according to claim 1 , wherein the blast-peening step includes adjusting angles of blast-peening between nozzles of the centrifugal impellers and the metal board.

6. The method according to claim 1 , wherein each of the centrifugal impellers includes a program-controllable motor, such that rotational speeds of the centrifugal impellers may be adjusted.

7. The method according to claim 1 , wherein the phosphatizing step includes using manganese phosphate solution or zinc phosphate solution.

8. The method according to claim 1 , wherein a thickness of the oxidized layer removed in the blast-peening step is greater than 10 μm.

9. A method for treating and phosphatizing a metal board without using acid, comprising:

performing a degreasing step, wherein a degreasing agent is provided to remove grease and dirt from a surface of the metal board;

performing a blast-peening step by blasting and peening polygon blast-peening granules on the surface of the metal board through centrifugal impellers to remove an oxidized layer;

performing a washing step to wash the surface of the metal board, so as to remove powders generated from the blast-peening step;

performing a phosphatizing step to form a phosphate coating on the surface of the metal board, so as to provide protection;

performing another washing step to wash off remaining phosphatizing agents from the metal board;

performing a rustproofing step to apply a rustproofing agent on the metal board;

performing a drying step to dry the metal board; and

performing a surface real-time observation step, wherein a detector is used to detect a status of removing the oxidized layer from the surface of the metal board in real-time, and wherein, when detecting that the powder generated from removing the oxidized layer has a characteristic in the air that undergoes a change, the blast-peening step is stopped.