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Product Description

For galvanized coils, the sheet steel is immersed in a molten zinc bath to make a sheet of zinc coated on its surface. It is mainly produced by continuous galvanizing process, that is, the rolled steel plate is continuously immersed in a plating tank with zinc melted to make galvanized steel plate; alloyed galvanized steel plate. This kind of steel plate is also manufactured by hot dip method, but immediately after being out of the tank, it is heated to about 500 ℃ to form an alloy coating of zinc and iron. This galvanized coil has good paint adhesion and weldability.

Classification code

(1) The classification and code of performance level shall be as specified in Table 1.
Table 1 Performance classification and code
level Performance level code scope of
application General purpose 01
Mechanical occlusion 02 Zinc layer weight code shall not exceed Z350
stamping 03 Thickness range is ≥ 0.4mm Zinc layer weight shall not exceed Z275
deep drawing 04
Special killed steel deep drawing 05
None Aging super deep drawing 06
structure 220, 250, 280, 320, 350, 400, 450, 550 steel plates with thickness < 0.4mm are not applicable to 220, 250, 280 and 320 grades
(2) The type and code of the substrate are as specified in Table 2 .
Table 2 Types and codes of
substrates Types of substrates Codes of
cold-rolled coils and hot-
rolled pickled coils H
(3) Types of double-sided equal-thickness galvanized layers and the classification and codes of coating weights are as specified in Table 3. Upon agreement between the supplier and the buyer, steel sheets and strips with coating weights not listed in Table 3 can also be provided.
Table 3 Types of galvanized layers and classification and code of coating weights Coating weight of
zinc-iron alloy coating of galvanized layer
/(g/㎡) (double-sided) Code Coating weight/ (g/㎡) (double-sided) Code
(60) (Z60 ) (40) (ZF40)
80 (Z80) 60 (ZF60)
100 (Z100) 80 (ZF80)
120 (Z120) 100 (ZF100)
150 (Z150) 120 (ZF120)
180 (Z180) 150 (ZF150)
200 (Z200) 180 (ZF180)
220 (Z220)
250 (Z250)
275 (Z2750)
350 (Z350) 450
600 (Z600)
Note: The weight of zinc layer in parentheses should be negotiated by both parties.
According to the half of the coating weight listed in Table 3, respectively represent the different coating weights on the upper and lower surfaces, such as: Z40/90 or ZF30/50. The appearance of the low zinc layer weight surface may differ from the appearance of the high zinc layer weight surface.
(4) The classification and code of the surface structure of the zinc layer are as specified in Table 4.
Due to strain test sales, the 01~04 grade steel plates and strips that have been smoothed should be leveled by an effective leveling machine before processing to avoid slip lines. The 05 or 06 grades that have undergone skinning are non-aging skinned steel sheets and strips, which can avoid slip lines within 6 months. Table 4 Classification and code of zinc coating
surface structure and smooth surface the provisions of Table 5. Table 5 Classification and code of surface quality Surface quality code Common surface FA Advanced surface FB Advanced surface FC (6) The classification and code of surface treatment are as specified in Table 6. Table 6 Classification and code of surface treatment Surface treatment symbol Passivation C
Oiled O
paint seal L
phosphating P
untreated U
6.1 Passivation
galvanized layer Passivation treatment can reduce the occurrence of rust (white rust) under the storage and transportation conditions of humidity and temperature. However, the corrosion resistance of this chemical treatment is limited and, moreover, hinders the adhesion of most coatings. This treatment is generally not used in zinc-iron alloy coatings. Except for the smooth surface, as a routine, other types of galvanized coatings are passivated by the manufacturer.
6.2 Oiling
and oiling can reduce the corrosion of steel plates under humid storage and transportation conditions, and re-coating the steel plates and steel strips after passivation treatment with oil will further reduce the corrosion under humid storage conditions. The oil layer should be able to be removed with a degreaser that does not damage the zinc layer.
6.3 Lacquer seals
provide an additional anti-corrosion effect, especially fingerprint resistance, by applying a very thin film of a transparent organic coating. Improves lubricity during molding and acts as an adherent primer for subsequent coats.
6.4 Phosphating
Through phosphating treatment, galvanized steel sheets of various coating types can be coated without further treatment except for normal cleaning. This treatment can improve the adhesion and corrosion resistance of the coating and reduce the risk of corrosion during storage and transportation. After phosphating, it can be used with a suitable lubricant to improve the molding properties.
6.5 No treatment
Only when the orderer requests for no treatment and is responsible for it, the steel plates and strips supplied in accordance with this standard may not be subjected to surface treatment such as passivation, oiling, paint sealing or phosphating.





Corrugated Steel Sheet




JIS G3302 / JIS G3312 / ASTM A653M / A924M 1998
/ GBT12754-2006, GB/T9761-1988, GB/T9754-1988, 
GB/T6739-1996, HG/T3830-2006, HG/T3830-2006, 
GB/T1732- 93, GB/T9286-1998, GB/T1771-1991, GB/T14522-93



Raw material

310,310S,409,410,430,439,443,445,441 and so on




hot rolled/
cold rolled

pre-painted, hot rolled
/cold rolled

cold rolled

hot rolled/cold rolled







T Bending


≤ 3T/4T


Anti-MEK  Wiping


Zinc coating


Color options

RAL Color System or as per buyer’s color sample.

Type of 
coating structure


2/1 or 2/2 coating, 
or customized


2/1 or 2/2 coating, 
or customized

Coil weight

or as you required

or as you required

or as you required

or as you required


Coil or Plate


big / small / no spangle



Soft---full hard

Supply ability(tons per year/production lines)





Payment term

T/T; L/C; T/T & L/C



Delivery time

around 10-15 days after T/T payment or L/C is received.

Plating Definition

(1) Spangle coating of normal spangle coating
In the normal solidification process of zinc layer, zinc grains grow freely and form a coating with obvious spangle morphology.
(2) Minimized spangle coating
During the solidification process of the zinc layer, the zinc grains are artificially restricted to form the smallest possible spangle coating.
(3) Spangle-free spangle-free coating
is obtained by adjusting the chemical composition of the plating solution, and has no visible spangle morphology and a uniform coating on the surface.
(4) Zinc-iron alloy coating
The steel strip after passing through the galvanizing bath is heat treated to form an alloy layer of zinc and iron. The appearance of this coating is dark gray and has no metallic luster. It is easy to powder during the process, and is suitable for coatings that can be directly painted without further treatment except for general cleaning.
(5) Differential coating of differential coating
For both sides of the galvanized steel sheet, coatings with different zinc layer weights are required.
(6) Skin pass skin pass
is a cold rolling process with a small deformation amount performed on a galvanized steel sheet for one or more of the following purposes.
Improve the surface appearance of galvanized steel sheet or be suitable for decorative coating; make the finished product not see the phenomenon of slip line (Lydes line) or crease during processing to minimize temporarily, etc.

rollCertificates and ClientsApplication industry

The main reasons for the peeling of the zinc layer are: surface oxidation, silicon compounds, the cold rolling emulsion is too dirty, the oxidizing atmosphere in the NOF section and the dew point of the protective gas are too high, the air-fuel ratio is unreasonable, the hydrogen flow rate is low, the furnace has oxygen infiltration, strip steel The temperature of entering the pot is too low, the furnace pressure in the RWP section is too low, the suction of the furnace door is too low, the furnace temperature in the NOF section is too low, the grease is not fully evaporated, the aluminum content of the zinc pot is too low, the unit speed is too fast, the reduction is insufficient, and the zinc solution stays in the liquid The time is too short and the coating is too thick.
The reasons for the occurrence of white rust and black spots are: black spots are formed by further oxidation of white rust.
The main reasons for white rust are:
(1) Poor passivation, insufficient or uneven thickness of the passivation film;
(2) No oil on the surface or residual water on the surface of the strip;
(3) Water on the surface of the strip during coiling;
(4) Passivation is not completely dried;
(5) It is wet or wet by rain during transportation or storage;
(6) The storage time of the finished product is too long;
(7) The galvanized sheet is in contact with or stored with other corrosive media such as acid and alkali. together.
The finished product is allowed to be stored in the warehouse for a maximum of three months to avoid oxidation caused by storage for too long.

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