"GB/T 18570.2-2009 Assessment of surface cleanliness of steel surfaces prepared before coating Coatings, Part 2: Laboratory determination of chlorides on cleaned surfaces" specifies laboratory methods for the determination of water-soluble chlorides on steel surfaces. This standard applies to the determination of chlorides on steel surfaces before, during or after cleaning, as well as surfaces that have been coated with Coatings. Its main purpose is to evaluate the cleanliness of steel surfaces through laboratory analysis to ensure that no chlorides remain on the surface before coating, thereby improving the adhesion and durability of coatings. The standard is managed by the China Shipbuilding Industry group company, released on March 9, 2009, and officially implemented on November 1, 2009.