| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a ferritic-stainless steel excellent in ridging resistance without lowering the productivity. SOLUTION: The method for manufacturing the ferritic-stainless steel is performed through the following processes. A slab for this steel has the compositions composed by mass% of 0.040-0.100% C, 0.20-1.00% Si, 0.30-1.00% Mn,≤0.040% P,≤0.010% S,≤0.45% Ni, 16.0-18.0% Cr,≤0.50% Mo,≤0.30% Cu,≤0.050% N and the balance Fe with inevitable impurities, and satisfies 55%≤an austenite potential (following Formula 1)≤65%, wherein Formula 1 is expressed by austenite potential(%)=288(%C)+350(N%)+22(%Ni)+7.5(%Mn)-18.75(%Cr)-54(%Si)+338.5. After heating the slab in the range of 1,000-1,200°C, a hot-rougher rolling having≥30% rolling-reduction ratio/1 pass is performed at 2 passes or more with a rougher rolling mill and thereafter, the rolled steel is held for 1 min or more. After the rough-rolling, a hot-finished rolling having≥30% rolling-reduction ratio/1 pass of the high rolling-reduction of the finishing rolling is performed at 3 passes or more with a reversible rolling mill providing heat insulating furnaces at both sides of the finish-rolling mill, while holding the steel sheet temperature to≥850°C with the above heat insulating furnace. Successively, after performing a butch-annealing under soaking at≥900°C for≥4 hours, the natural cooling is performed until the steel sheet temperature becomes 600°C. COPYRIGHT: (C)2011,JPO&INPIT
|
