| 摘要 |
A method of making steel is provided wherein low carbon steel is heat-treated directly in connection with the hot-rolling to a so-called dual-phase steel the structure of which is characterized by fine-grained, polygonal ferrite and therein dispersed grains of martensite. The mainly in austenitic state hot rolled steel after finished hot rolling is cooled down to a predetermined temperature within the interval 800-650 DEG C and kept there during more than 1 minute, thereafter cooled to a temperature below 450 DEG C with a cooling rate exceeding 10 DEG C/second. The method is used for making steel strip exhibiting high strength and formability. |
