| 摘要 |
<p>A rolled steel product is made from molten steel and pieces of steel scrap of an analysis approaching that of the molten steel by feeding the scrap and molten steel into an ingot mold at the same time. Prior to feeding, the scrap is sized, cleaned and then placed in a cylinder arranged adjacent to and above the mold. The discharge end of the cylinder is closed with a gate and the scrap compressed by moving a plunger several inches to compress it in the cylinder. The scrap is then heated to remove the moisture, after which the gate is removed and the plunger moved forwardly at a steady rate to push the scrap into a chute leading to the mold. At the same time, molten steel is poured into the mold. The ingot is permitted to solidify and then heated in a soaking pit to rolling temperature after which it is rolled to semi-finished form, such as a slab, billet or bloom. The combination of heat and pressure in this operation welds or bonds the pieces of scrap to the surrounding metal and to each other, forming a unitary structure. The semi-finished form is then re-heated and rolled to the desired finished hot rolled product, such as sheet, strip, rod, bar or structural shape. This second heating and hot rolling operation with its combination of heat and pressure and very substantial reduction of area supplements and completes the pressure welding process initiated in rolling the ingot to semi-finished form. The steel is then ready for fabrication or use, or for further cold rolling or cold drawing in the same manner as standard hot rolled steel mill products. The end product is a plurality of small steel scrap particles interspersed in and bonded to a mass of steel.</p> |
