Metal sheet with zinc hydroxysulfate/zinc sulfate-based protection layer

A coiled and stored steel sheet, wherein the coiled and stored steel sheet consists of:

• a steel substrate;
• a multilayer coating covering at least one face of the steel substrate, the multilayer coating consisting of a layer of zinc deposited by electrodeposition and a layer of zinc and magnesium over the layer of zinc;
• a zinc hydroxysulfate/zinc sulfate-based temporary protection layer applied over the multilayer coating, the temporary protection layer having a sulfur content greater than or equal to 0.5 mg/m2 and less than or equal to 30 mg/m2;
• an optional film of oil applied over the zinc hydroxysulfate/zinc sulfate-based temporary protection layer;
• wherein the zinc hydroxysulfate/zinc sulfate temporary protection layer is stabilized by the magnesium in the coating such that, when tested by a test performed in a humidity and temperature controlled corrosion-test chamber in accordance with DIN EN ISO 6270-2, less than 10% of a surface of a test piece is visually altered after 10 cycles with 1 g/m2 oil or after 15 cycles with 1.2 g/m2 of oil.

A coiled and stored steel sheet, wherein the coiled and stored steel sheet consists of:

• a cold-rolled steel substrate;
• a multilayer coating consisting of a layer of zinc and a layer of zinc and magnesium over the layer of zinc;
• a zinc hydroxysulfate/zinc sulfate-based temporary protection layer applied over the multilayer coating, the temporary protection layer having a sulfur content greater than or equal to 0.5 mg/m2 and less than or equal to 30 mg/m2 wherein the zinc hydroxysulfate/zinc sulfate temporary protection layer is stabilized by the magnesium in the multilayer coating to prevent the formation of zinc carbonates in the presence of atmospheric CO2;
• an optional film of oil applied over the zinc hydroxysulfate/zinc sulfate-based temporary protection layer.

A coiled and stored steel sheet, wherein the coiled and stored steel sheet consists of:

• a steel substrate;
• a multilayer coating covering at least one face of the steel substrate, the multilayer coating produced by heat treating a layer of zinc deposited by electrodeposition and a layer of magnesium deposited by vacuum deposition over the layer of zinc;
• a zinc hydroxysulfate/zinc sulfate-based temporary protection layer applied over the multilayer coating, the temporary protection layer having a sulfur content greater than or equal to 0.5 mg/m2 and less than or equal to 30 mg/m2;
• an optional film of oil applied over the zinc hydroxysulfate/zinc sulfate-based temporary protection layer;
• wherein the zinc hydroxysulfate/zinc sulfate temporary protection layer is stabilized by the magnesium in the coating such that, when tested by a test performed in a humidity and temperature controlled corrosion-test chamber in accordance with DIN EN ISO 6270-2, less than 10% of a surface of a test piece is visually altered after 10 cycles with 1 g/m2 oil or after 15 cycles with 1.2 g/m2 of oil.

A coiled and stored steel sheet, wherein the coiled and stored steel sheet consists of:

• a steel substrate;
• a multilayer coating covering at least one face of the steel substrate, the multilayer coating consisting of a layer of zinc deposited by vacuum deposition and a layer of zinc and magnesium over the layer of zinc;
• a zinc hydroxysulfate/zinc sulfate-based temporary protection layer applied over the multilayer coating, the temporary protection layer having a sulfur content greater than or equal to 0.5 mg/m2 and less than or equal to 30 mg/m2
• an optional film of oil applied over the zinc hydroxysulfate/zinc sulfate-based temporary protection layer;
• wherein the zinc hydroxysulfate/zinc sulfate temporary protection layer is stabilized by the magnesium in the coating such that, when tested by a test performed in a humidity and temperature controlled corrosion-test chamber in accordance with DIN EN ISO 6270-2, less than 10% of a surface of a test piece is visually altered after 10 cycles with 1 g/m2 oil or after 15 cycles with 1.2 g/m2 of oil.

A coiled and stored steel sheet, wherein the coiled and stored steel sheet consists of:

• a steel substrate;
• a multilayer coating covering at least one face of the steel substrate, the multilayer coating made by heat treating a layer of zinc deposited by vacuum deposition and a layer magnesium deposited by vacuum deposition over the layer of zinc, consisting of a layer of zinc deposited by vacuum deposition and a layer of zinc and magnesium over the layer of zinc;
• a zinc hydroxysulfate/zinc sulfate-based temporary protection layer applied over the multilayer coating, the temporary protection layer having a sulfur content greater than or equal to 0.5 mg/m2 and less than or equal to 30 mg/m2
• an optional film of oil applied over the zinc hydroxysulfate/zinc sulfate-based temporary protection layer;
• wherein the zinc hydroxysulfate/zinc sulfate temporary protection layer is stabilized by the magnesium in the coating such that, when tested by a test performed in a humidity and temperature controlled corrosion-test chamber in accordance with DIN EN ISO 6270-2, less than 10% of a surface of a test piece is visually altered after 10 cycles with 1 g/m2 oil or after 15 cycles with 1.2 g/m2 of oil.