NIPPON STEEL CORPORATION

Corrosion resistance of weld zones

Quality

Corrosion resistance of weld zones (as welded)

Generally, the heat affected area on coated steel by arc welding or spot welding reduces corrosion resistance because the coating layer is melted or vaporized. The welded portion on ZAM® however, is less likely to suffer from red rust than other types of coated steels.

Appearances of arc weld zones after salt spray test

Lapse of time: 2,000h
Lapse of time: 2,000h ZAM Thickness: 2.3 mm 90/90 g/m2
Lapse of time: 4,000h
Lapse of time: 4,000h ZAM Thickness: 2.3 mm 90/90 g/m2

ZAM® Thickness: 2.3 mm 90/90 g/m2

Lapse of time: 2,000h
Lapse of time: 2,000h Zn-5% Al alloy coated steel Thickness: 2.3 mm 90/90 g/m2 Weld beads
Lapse of time: 4,000h
Lapse of time: 4,000h Zn-5% Al alloy coated steel Thickness: 2.3 mm 90/90 g/m2 Appearances of arc weld zones after salt spray test

Zn-5% Al alloy coated steel Thickness: 2.3 mm 90/90 g/m2

Reference scale: 20mm

Appearances of spot weld zones after salt spray test

Lapse of time: Before test
Lapse of time: Before test ZAM Thickness: 2.3 mm 90/90 g/m2 Appearances of spot weld zones after salt spray test
Lapse of time: 2,000h
Lapse of time: 2,000h ZAM Thickness: 2.3 mm 90/90 g/m2 Appearances of spot weld zones after salt spray test
Lapse of time: 4,000h
Lapse of time: 4,000h ZAM Thickness: 2.3 mm 90/90 g/m2 Appearances of spot weld zones after salt spray test

ZAM® Thickness: 2.3 mm 90/90 g/m2

Lapse of time: Before test Zn-5% Al alloy coated steel
Thickness: 2.3 mm 90/90 g/m2 Appearances of spot weld zones after salt spray test
Lapse of time: 2,000h Zn-5% Al alloy coated steel
Thickness: 2.3 mm 90/90 g/m2 Appearances of spot weld zones after salt spray test
Lapse of time: 4,000h Zn-5% Al alloy coated steel
Thickness: 2.3 mm 90/90 g/m2 Appearances of spot weld zones after salt spray test

Zn-5% Al alloy coated steel Thickness: 2.3 mm 90/90 g/m2

Reference scale: 10mm