1. bending properties
In accordance with the requirements specified in the contract for aluminium alloys sheet for ships, the bending test should not occur in accordance with the prescribed bending radius.
2. exfoliation corrosion resistance
Exfoliation corrosion test of marine grade aluminum alloys sheet of 5XXX series H116 and H321.
Marine grade aluminium alloys sheet for 5XXX series H116 and H321 states. When the contract is marked as "hull plate outside the ship" or "direct contact with the sea for a long time", exfoliation corrosion test shall not appear PB grade exfoliation corrosion.  
7A19 grade T76 aluminium alloys sheet for ships shall not appear E grade exfoliation corrosion after exfoliation corrosion test.
 
3.Intergranular corrosion resistance
The maximum corrosion depth of intergranular corrosion of 5XXX H116 and H321 aluminum alloy plates is less than 3.
 
4. fold tissue
No delamination is allowed in aluminium alloys plate for ships with thickness of not less than 6.5mm.
 
5. microstructure
The microstructure of quenched marine grade aluminium alloys plate is not allowed to overheat.  
6. ultrasonic inspection
Aluminium alloys plate for ships generally does not carry on the ultrasonic flaw detection. For marine grade aluminium alloys plate with thickness greater than or equal to 10mm, if the buyer needs ultrasonic testing, it should be marked in the contract.
 
7. appearance quality
The surface of aluminium alloy sheet for ships should be smooth, smooth and well processed, and the edge of Chinese cabbage should be neat and without burr.
 
The marine grade aluminium alloys sheet surface cracks are not allowed, creases, nitrate marks, delamination, corrosion, oxidation inclusion, peeling, bubble, serious metal and nonmetal material or mechanical damage such as indentation defects affect the subsequent processing using live.  
Allow the plate surface does not affect the use, a slight dent, bumps, bruises, wounds, sticky marks, but the depth should not exceed the negative deviation of plate thickness allowed half, should not make the sheet thickness deviation beyond the allowable range.
 
On behalf of the consent of the user or user consent, allowed for the dressing of plate surface defects by machining or grinding, trimming depth shall not exceed the allowable thickness of negative deviation, and are not allowed to have any adverse effects on the material. Unless otherwise agreed, all repairs shall be carried out under the presence of customer or user representatives, and welding repair shall not be permitted.