DBS BRIDGE STEEL / PRINTECH, REAL ZINC, ZINC

Product Introduction

Outstanding weather resistance, with special paints having high weather resistant polyester resin
Enhanced durability to improve the shortcomings of Si-P/E, particularly unfavorable workability
SUNTEK : Dongbu Steel's brand name for high durable polyester products.

Exterior materials
Sandwich panels

Cross section of painted product

Applied materials

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 of Hot-dip Galvanized(GI) Steel Sheets

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.

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 25μ).
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
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 sheet, is 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 cteel cheets	CRACK FREE
5% Zn/AL Alloy coated cteel cheets	Anti-corrosion, Workability	GALFAN
55% Zn/AL Alloy coated cteel cheets	Construction in bad condition	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)	0.20~1.6t	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
HO-TDIP 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)	0.20~0.6t	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˚	500hours 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	1000hours Good	JIS Z 0230
Film hardness test	M.E.K Rubbing	40Times Good	DS-B-I-1112

Applied Specifications

KS D 3520
JIS G 3312
ASTM A 653