| 摘要 |
PURPOSE:To considerably improve the toughness of the medium-thickness plate of high-Cr ferrite-base stainless steel by hot-rolling said stainless steel under the specific conditions then applying heat treatment thereto. CONSTITUTION:The ferrite-base stainless steel ingot containing Cr; 17-40%, C<0.01%, N<0.04%, and further, if necessary, Mo<4%, Ni<4% is hot-rolled to a plate material. The final pass of this rolling process is accomplished under the conditions of temperatures 500-750 deg.C and drafts 20-80%. In the case of producing medium-thickness plates of 6mm-15mm thickness, the hot-rolled structure of the steel plate having been hot-rolled under the above conditions are thermally low in stability and therefore it is annealed at 750-900 deg.C to improve the structure to fine grains of about 8-9 in ASTM crystal grain number. Or from the results of impact test, softening heat treatment of 5-10 minutes at 900-1,000 deg.C may be further applied thereto to improve its impact characteristic. |
