| 摘要 |
<p>Prior to rolling, the Pb sheet (a) is clad on both sides with a laminated prod. (b), which is itself made by rolling down to the required thickness. Prod. (b) is Pb (b1) coated with a layer (b2) of tin or tin alloy. Layer (b1) is next to Pb (a), so both surfaces of the clad sheet (bab) consist of Sn or Sn alloy (b2). The clad sheet nbab) is rolled into foil in a single pass, using a high tension, i.e. back-pull, on the sheet (bab) on the inlet side of the rolling mill. By coating the initial Pb sheet (a) with a layer of Sn or Sn alloy, a much larger redn. in the thickness of the sheet can be obtd. in single pass rolling. For example, a clad sheet 1 mm. thick can be rolled down to 50-10 mu m in a single pass, which is redn. of over 90%, as compared with only 50% in conventional processes.</p> |
