| 摘要 |
<p>PURPOSE:The captioned steel product of improved corrosion resistance, weldability, workability and coating characteristic by applying two layers of the Zn plating layer of the specified thickness on an under layer and the Mn plating layer of the specific thickness on the upper layer to one or both surfaces of the steel material. CONSTITUTION:A zinc plating layer of 0.4 to 8.4mu in plating thickness is applied to a hot or cold rolled steel plate and further two players of the Mn plating layer of 0.6 to 7mu in thickness are applied thereon to at least one surface thereof. The zinc plating of the under layer may be executed by either hot dipping or electroplating. In the case of electroplating of zinc, a sulfate bath or chloride bath may be utilized. The Mn plating of the upper layer may be readily accomplished by the electroplating method using a sulfate bath or chloride bath. Antirust oil or working oil is coated or prime-coating of painting is applied to the non-plating surface of one side.</p> |
