DBS BRIDGE STEEL / PRINTECH, REAL ZINC, ZINC

Product Introduction

Anti-pollution paint is aimed at improving resistance against stain, oxidation and polluters including carbon, the main culprit of air pollution, by highlighting the resin's tight-knit structure on the weather-resistant coating's upper layer.

Dongbu Steel produces Sun-Clean prepainted steel sheet.

- Sandwich panels
- Factory complex buildings

Product Features

1
Compared old coated steel sheet, dust or other matters will not stick

2
With excellent acid resistance and alkaline properties, prepainted steel sheet is used for panel materials and exterior materials for factories.

3
Compared to old steel sheet, it has excellent surface conditions against pollution matters such as sulfurous acid gas.

4
Treatments, such as building cleaning, are made simple because of excellent contamination resistance.

5
Excellent atmospheric corrosion resistance

Fundamentals of Product

Uses a very fine resin, which has hydrophilic properties. It protects against pollution matters that stick when it. rains improved contamination resistance of by melamine on the surface, pollution matters cannot penetrate the surface although cuts are contaminated.

Property Comparison

Carbon black pollution assessment results

☞ Sunclean has been proven to possess the greatest anti-pollution properties, showing the least amount of change in color in comparison with conventional steel sheet

Drop 0.5% carbon black solution on the Sunclean product and heat at 80˚C for 24~48 hours. Wash with water and examine the color difference.

☞ An easy method to measure pollution resistance.

Assessment of weather resistance and anti-corrosion properties

	Anti-pollution 304	POLYESTTER steel plate	Remarks
Q.U.V	0.5	0.47
W.O.M	0.42	0.48
Corrosion	None	None	SALT SPRAY TEST

Test Hours: 1000 hrs
* The value yielded from the color difference through naked eye observation.
* Color differences measured by the naked eye and the comparator are the same

Basic property assessment

	Anti-pollution Steel Sheet	P/E	Remarks
Workability	2T 4 point	2T 4 point
Pencil hardness	2H	2H
MEK	80 trials and more	40 trials and more

Cross section of painted product

Applied material

Hot-dip galvanized steel sheet (KS D 3506, GI)
The cold rolled steel sheet passes through a molten zinc pot containing 97% zinc (0.03% or less AL), undergoing the galvanizing process, which gives each side of the sheet and equal thickness of coating.

Depending on the surface treatment of the plated sheet, the sheet is categorized into regular spangle, minimized spangle, or zero spangle ultra smooth, which are symbolized as R, M, Z, respectively. Prepainted steel sheet produced by Dongbu Steel uses ultra smooth material in the production process.

Surface types for hot-dip galvanized steel sheet (GI)

While an increased volume of coating enhances the anti-corrosion properties of galvanized steel sheet, the workability is inevitably decreased. Anti-corrosion properties, workability, tension, and elongation must be taken into consideration when selecting plates.

1)
The normal wall thickness of galvanized steel plates refers to the thickness of pre-coated steel plates. The clearance of the machine, therefore, must account for the thickness of the zinc plating indicated in Table 1 as well as the coating thickness (usually 255μ).

2)
Zinc flacks may stick inside the metallic pattern during the deep drawing process, requiring extra caution be taken as this may damage the coating's exterior

3)
Lubrication oil used in treatment shall not contain chlorine or phosphoric acid, which reacts to zinc. Table 1 shows the zinc weight and coating thickness for hot-dip galvanized steel sheet used for prepainted steel sheet. These figures are adopted by KS (Korean Standards), JIS (Japan Industrial Standards), and ASTM (American Society for Testing Materials).

Table 1 - Weight and thickness of zinc coating

Zinc Coating WeightSymbol	Z 06	Z 08	Z 13	Z 12	Z 18	Z 20	Z 22	Z 26	Z 27
Zinc Coating Thickness(㎜)	0.013	0.017	0.021	0.026	0.034	0.040	0.043	0.049	0.054
Weightg/㎡(Both side)	90	120	125	183	244	285	305	345	381
ASTM A 525	G-30		G-40	G-60		G-90			G-115

Special hot-dip galvanized steel sheet (KS D 3770, SGL)
Zn/AL alloy coated steel sheet as well as galvanized sheets, are available for products requiring particularly high-workability and high-durability. Table 2 lists the applications and contents of these sheets.

Table 2 - Applications of Zn/AL alloy coated steel sheet

Type	Application	Remarks
Regular hot-dip galvanized iron	Regular use
1% Zn/AL Alloy Coated Steel Sheets	CRACK FREE
5% Zn/AL Alloy Coated Steel Sheets	Anti-corrosion, workability	GALFAN
55% Zn/AL Alloy Coated Steel Sheets	Construction in poor conditions	SUPERGALUM (Dongbu Steel Brand) GALVALUME

Electrolytic galvanized steel sheet (KS D 3528, EGI)
The surface of the cold rolled steel sheet (KS D 3512) undergoes a dull finishing treatment, followed by a double-sided coating process (zinc weight: 13g~25g/㎡). Five products are available depending on the coating weight. Electro galvanized Iron (EGI) is usually used in home electrical appliances that require extensive workability. Due to its low zinc weight, EGI cannot be used for products that require anti-corrosion properties.

Aluminum steel sheet (KS D 6701)
While aluminum is light in specific gravity, it possesses high tensile strength. Due to its superb anti-corrosion properties, aluminum is widely used in the production of aircrafts, automobiles, containers, blinds, ceiling material, and composite panels.

Cold rolled stainless steel sheet (KS D 3698)
Due to its anti-corrosion and chemical resistant properties that far exceed other steel products, stainless steel sheet is optimum for products that require extremely high levels of corrosion resistance and durability.
Stainless Steel Sheet takes is produced from Iron/Chrome or Nickel/Chrome alloy. STS 304 or STS 430 are used mainly for PCM (JIS uses the symbol SUS).

Raw Materials	Size		Related specification	Characteristics
Raw Materials	Thickness	Width	Related specification	Characteristics
COLOR-ROLLED STEEL (CR)	0.25~1.6t	600~1380㎜	ASTM A-366 KS D 3512 JIS G 3141	Excellent formability Excellent weldability Excellent surface Bright surface
HOT-DIP GALVANIZED STEEL (GI)	0.25~1.6t	600~1380㎜	ASTM A-526 KS D 3506 JIS G 3302	Corrosion resistance
ELECTROLYTIC GALVANIZED STEEL (EGI)	0.35~1.6t	600~1380㎜	ASTM A-591 KS D 3528 JIS G 3313	Excellent formability
GALVANNEALED STEEL (GA)	0.35~1.6t	600~1380㎜	ASTM A-526 KS D 3506 JIS G 3302	Good weldability Corrosion resistance
HOT-DIP ALUMINIZED STEEL (AL-COT)	0.35~1.6t	600~1380㎜	ASTM A-463 KS D 3544 JIS G 3314	Heat resistance Corrosion resistance Heat reflectiveness
BLACK PLATE (BP)	0.25~0.6t	600~1380㎜	ASTM A-623 KS D 3516 JIS G 3303	Excellent lackerability Excellent workability Heat resistance
ALUMINUM STEEL (AL)	0.3~1.6t	600~1380㎜	ASTM B-209 KS D 6701 JIS G 4000	Corrosion resistance High durability
STAINLESS STEEL(STS)	0.3~1.6t	600~1380㎜	ASTM A-895 KS D 3698 JIS G 4305	Corrosion resistance High durability Chemical resistance
SuperGalum (SGL)	0.3~1.6t	600~1380㎜	ASTM A-792 KS D 3770 EN 10215	Heat resistance Corrosion resistance Heat reflectiveness High durability

Size availability

Test items

Test item	Test method	Test result	Related specification
Cross cut test	100/100 TAPING TEST	Good	KS D 3520
Pencil hardness test	45˚, 1H and over	Good	KS D 3520
Bending test	180˚×3T	Good	KS D 3520
Impact test	500g×12.7㎜φ×500㎜H	Good	KS D 3520
Salt water spray test	5%Nacl 35˚	750hours Good	KS D 9520 JIS Z 2371
Resistance to chemicals	5%H₂SO₄×5Hr 5%NaOH×5Hr	Good Good	DS-B-I-1112
Accelerated weathering test	Weather-O-Meter	750hours Good	JIS Z 0230
Film hardness test	M.E.K Rubbing	80Times Good	DS-B-I-1112

Applied specifications

KS D 3520
JIS G 3312
ASTM A 653

Basic color

1	Compared old coated steel sheet, dust or other matters will not stick
2	With excellent acid resistance and alkaline properties, prepainted steel sheet is used for panel materials and exterior materials for factories.
3	Compared to old steel sheet, it has excellent surface conditions against pollution matters such as sulfurous acid gas.
4	Treatments, such as building cleaning, are made simple because of excellent contamination resistance.
5	Excellent atmospheric corrosion resistance

1)	The normal wall thickness of galvanized steel plates refers to the thickness of pre-coated steel plates. The clearance of the machine, therefore, must account for the thickness of the zinc plating indicated in Table 1 as well as the coating thickness (usually 255μ).
2)	Zinc flacks may stick inside the metallic pattern during the deep drawing process, requiring extra caution be taken as this may damage the coating's exterior
3)	Lubrication oil used in treatment shall not contain chlorine or phosphoric acid, which reacts to zinc. Table 1 shows the zinc weight and coating thickness for hot-dip galvanized steel sheet used for prepainted steel sheet. These figures are adopted by KS (Korean Standards), JIS (Japan Industrial Standards), and ASTM (American Society for Testing Materials).