Manufacture of Economical As-hot-rolled Dual Phase Steel in WISCO CSP Plant

摘要

The pilot production of 580MPa as-hot-rolled dual phase strip at WISCO CSP Plant is introduced. Two dual phase steel compositions , one plain C-Mn -Si and the other C-Mn-Si-Cr were seleced and produced successfully by controlled rolling and controlled cooling with ultra fast cooling capacity, both tensile strengih achieve 580 MPa. Comparison of both steels mechanical performance and microstructure shows that the low cost C-Si -Mn steel yers C-Si -Mn -Cr , has lower yield stress , lower yield ratio , and higher elongation. Though lower amounts of niajtensite , the island niartensite is distributed among the ferrite grain boundaries more uniformly, the specific measures of controlling ferrite precipitation and promoting martensite formation are put forward.