| 摘要 |
<p>A method of producing high strength hot-rolled steel sheets for automotive wheel rim and disc application comprising the steps of making a liquid steel in a basic oxygen furnace (BOF) having composition in wt% C- 0.04 to 0.08, Mn- 1.15 to 1.3, Si- 0.1 to 0.2, S- 0.008 max, P - 0.025 max, Al- 0.01 to 0.07, N- 0.005 max, Mo- 0.08 to 0.12 and Ti- 0.04 to 0.05; refining and degassing of nitrogen of the said steel is carried in a ladle furnace; continuous casting the liquid steel into slab casting; hot rolling the slab casting into strip of 1100 mm width and 3.2 mm thickness at FRT 850-920°C and coiling the strips at coiling temperature 500-630°C to obtain high tensile (600 MPa minimum) with excellent elongation, hole expansion ratio and high endurance fatigue strength.</p> |
