| 摘要 |
A method of and apparatus for hot-rolling non-ferrous metal bar in a plural stage rolling mill are disclosed. Each stage of the rolling mill is provided with a plurality of work rolls which have a predetermined hardness and toughness depending on their intended use in the rolling mill to improve the uniformity of the useful life of the rolls among the various stages of the mill. A method of heat treating the work rolls and an improved forged steel work roll are also disclosed. The steel used to make the rolls is a forged chromium-molybdenum alloy steel having a chromium content in the range of 4.0 to 6.0 percent. The heat treatment process provides the working surfaces of the rolls with a dense, tightly-adhering oxide layer to protect the rolls from the high temperatures and pressures encountered during the hot-rolling operation. |
