1, the material of large galvanized wire: zinc ingot: should not be lower than the no. – zinc stipulated in GB470; Sulfuric acid: grade 1 concentrated sulfuric acid according to GB534; Hydrochloric acid: grade 1 concentrated hydrochloric acid in accordance with GB534; Ammonium chloride: should comply with the provisions of GB2946 ammonium chloride level 1.
2, appearance: coating surface continuous and practical, smooth; The installation and bonding of plated parts are not allowed to have flow hanging, dripping or melting. The surface of the plated parts shall be free from defects such as leakage plating and dew iron, but the defects are allowed to exist under the following circumstances; Leakage area is less than 0.5mm diameter spots; Regardless of the size of the plating piece, the spots in the lake plating area of 0.5mm- Imm diameter shall not exceed 3 points per square centimeter, and the total number of spots in the plating piece shall not exceed 10 points; In the non-connection or non-junction Angle, the height of not more than 1.5mm flow hanging drip or slag; There are scars when plating parts contact with hanging tools and operating tools, but no dew iron.
3. Zinc adhesion and zinc layer thickness: when the thickness of plated parts is 3mm~4mm, zinc adhesion should be less than 460g/m, that is, the average thickness of zinc layer is not less than 65um; When the thickness of plated parts is greater than 4mm, the zinc adhesion should not be less than 610g/m, that is, the average thickness of zinc layer is not less than 86um; Coating uniformity, galvanized layer is basically uniform with copper sulfate solution test etching five times no dew iron; Coating adhesion, the zinc layer of plated parts should be firmly combined with the basic metal with enough adhesion strength, after hammer test does not fall off, not convex.
4, to be plated requirements: to be plated surface should be smooth, without pickling method can not remove the pollution, such as oil reading, grease, cement, asphalt and other harmful impurities; All welds of welded members shall be sealed without air; Pipes and containers must have holes for exhaust and zinc intake; The workpiece shall be finished welded steel pipe without thread, if thread shall be protected. Test method: Zinc adhesion was measured by magnetic thickness gauge and zinc layer thickness was measured directly. The uniformity of coating was determined by copper sulfate solution etching test method.
5, stretching method: zinc layer adhesion, zinc layer thickness, zinc layer uniformity, adhesion is disputed, take the sample and the product under the same process conditions galvanized; Do the test, do not meet the requirements of this standard for unqualified products; Product factory sampling test method, the first time will not case, then according to the relevant provisions sampling test, if still unqualified, judge this batch of products is unqualified. Surveyor’s bank: Qualified plated parts can only be listed in the qualified office after being certified by a full-time inspector; Qualified products should be stacked neatly according to various specifications.
Post time: 05-11-21