Galvanized steel sheet - Galvanized steel sheet

Also called galvanized iron or galvanized steel sheet. Thin mild steel sheet with carbon content of 0.1% or less is plated with zinc to give it excellent corrosion resistance. Galvanizing is done by passing a cut sheet cut to a certain size through molten flux, lead, and zinc tanks in sequence, or by continuous galvanizing, passing a rolled coil through a molten zinc tank at high speed while unwinding it. Galvanized steel sheet is weak against acids, but shows excellent corrosion resistance in near-neutral environments. In such environments, Zn has better corrosion resistance than Fe, and the life of the plating is determined by the thickness of the plating, but the thickness can be changed over a wide range from about 8 μm to about 100 μm depending on the work method. Galvanized steel sheet is used in a wide range of applications, from car bodies to building materials such as roof panels, gasoline cans, and washing machine parts. The flower pattern seen on the surface of galvanized steel sheet is zinc crystal called spangle, and although it has no particular relation to corrosion resistance, it is designed to be large and beautiful to increase the commercial value.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

トタン，亜鉛鉄板ともいう．炭素量0.1％ 以下の薄い軟鋼板の表面に亜鉛をめっきして，すぐれた耐食性を与えたもの．一定の寸法に切断した切板を用いてフラックス，鉛，亜鉛の各溶融槽を順次通過させて亜鉛めっきを行う方法と，圧延コイルを巻きもどしながら高速度で溶融亜鉛槽を通過させる連続亜鉛めっきがある．亜鉛めっき鋼板は酸には弱いが，中性に近い環境ではすぐれた耐食性を示す．このような環境では，ZnはFeより耐食性がよく，めっきの寿命はめっきの厚さによって決まると考えてよいが，作業方法によってその厚さを約8 μm から100 μm 程度まで広い範囲に変えることができる．自動車の車体用から屋根板をはじめとする建築材料，ガソリン缶，洗濯機の部品など各方面にわたって用いられている．なお，亜鉛めっき鋼板の表面に見られる花模様は，亜鉛の結晶でスパングルとよばれ，耐食性にはとくに関係はないが，商品価値を高めるためにこれを大きく美しく生じさせるように工夫されている．

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