摘要 |
1467576 Heat-treating rails FRIED KRUPP HUTTENWERKE AG 23 July 1975 [16 Aug 1974] 30812/75 Heading C7A The head portion only, or the entire body, of a steel rail is quenched from the austenite region into water at < 80‹C to a temperature at or below that at which transformation to pearlite is completed. In a preferred embodiment the rail is cooled either from rolling temperature or from 800-850‹C into boiling water until its temperature is reduced to 100‹C. A number of rail steels are referred to within the following ranges CÀ4-À9, Si up to 1.3, Mn À6-1À7 with, in one example, CrÀ8-1À3. |