High quality grade galvanized sheet requirements include aspects of size, appearance, galvanized volume, chemical composition, shape, mechanical properties and packaging.
1. package
Cut into cut lengths of galvanized sheet and coil galvanized sheet packaging two kinds. General metal packaging, lined with waterproof paper outside to Tieyao child tying, tying securely to prevent friction between the interior galvanized sheet
2. Size
For standard (hereinafter referred to) are the recommended standard set out in galvanized sheet thickness, length and width and tolerance. In addition, the board width and length, width, volume is determined according to user requirements.
3. Exterior
Surface Condition: China Galvanized Corrugated Roof Sheet process due to the different treatment, surface state is different, such as the common spangles, fine spangle, smooth spangle, spangle-free surface phosphate processing and the like. Cut to cut lengths of galvanized sheet and galvanized coil must not affect the use of the presence of defects (detailed below), but not a normal part of a number of coils allows welding parts and so on.
4. Galvanized amount
Galvanized amount of standard values: a galvanizing capacity is an effective way of galvanized zinc coating thickness commonly used representation. Galvanized both sides have the same amount (ie equal thickness galvanized) and different amounts of galvanized both sides (ie the difference between thick galvanized) two. Galvanized amount in units of g / m2.
5. Mechanical behavior
(1) Tensile tests: Generally, only structures, stretching and deep drawing galvanized sheet has tensile performance requirements.
(2) Bending test: is the main item sheet measure process performance. But national standards for a variety of galvanized sheet demand is not consistent. General requirements for galvanized sheet bending 180o, the outer surface may not have the zinc layer from the plate group may not have cracked and broken.
6. chemical composition
The chemical composition of galvanized substrate requirements, different national standards requirements. As Japan is not required, the United States is required. Generally do not make product testing.
7. Shape
There are good and bad measure flatness two indicators, namely flatness and camber. The maximum allowable value of the standard plate flatness and camber are certain rules.
Listed below are the main foreign standards for galvanized sheet, for reference [4,5]:
JIS G3302 galvanized steel
JIS G3313 electro-galvanized steel sheet and strip
ASTM A525 General requirements for hot-dip galvanized sheet steel
ASTM A526 commercial grade hot-dip galvanized steel sheet
ASTM 527 bite molding grade galvanized steel sheet
ASTM 528 hot-dip galvanized steel sheet leveling deep
ASTM A361 roofing and siding with hot-dip galvanized steel sheet
ASTM A444 ditches with hot-dip galvanized steel sheet
ASTM A446 grade galvanized steel sheet structure
Cold galvanized First, the cold galvanizing OverviewCold galvanized also called electro-galvanized, is the use of electrolysis equipment will pipe degreasing, pickling, zinc salt into the composition of the solution, and connect the negative electrolysis equipment placed zincograph opposite pipe connected to the electrolysis positive power equipment, the use of electric current from the positive to the negative directional movement will be deposited in a layer of zinc on the tube, cold-plated fittings are galvanized after the first processing.Second, the cold galvanizing processCold galvanizing process used to protect the metal against corrosion, for the use of the zinc coating filler, a coating of using any method to be applied to protect the surface, forming a zinc coating filler After drying, the dried coating having a content of zinc (95%). Suitable for repair work (ie work in the repair process, the only place to be protected in the steel surface damage, as long as the repaired surface can be recoated). Cold galvanizing process for a variety of steel products and structures of corrosion, which galvanized the amount of small, only 10-50g / m2, its own poor corrosion resistance. But the use of electro-galvanized price is relatively cheaper.Third, cold galvanized and hot dip galvanized differenceCold galvanized (galvanized) and galvanized the most fundamental difference is the difference between the thickness of the zinc coating thickness larger electro-galvanized layer is typically only 20 ~ 30μm, sprayed zinc coating thickness is typically only about 100μm, dip coating thickness of the zinc layer is generally about 200μm. However, in either process, the thickness of the coating is not the same. General with a special coating thickness gauge to accurately detect the thickness of the coating industry.
Source : articlesbase.com
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