| 摘要 |
<p>The invention relates to a method of producing a cold-rolled band of dual-phase steel with a ferritic/martensitic structure. The inventive method consists in hot rolling a slab having a chemical composition which comprises, by weight, 0.01 % <= C <= 0.1 %, 0.05 % <= Mn <= 1 %, 0.01 % <= Cr <= 1 %, 0.01 % <= Si <= 0.5 %, 0.001 % <= P <= 0.2 %, 0.01 % <= Al <= 0.1 %, N <= 0.01 %, the remainder being iron and impurities resulting from the preparation thereof. The method also comprises the following subsequent steps consisting in: hot winding the band obtained at a temperature of between 550 and 850 °C; cold rolling the band with a reduction ratio of between 60 and 90 %; annealing the band continuously in the intercritical region; cooling said band to ambient temperature, in one or more steps, the rate of cooling between 600 °C and ambient temperature being between 100 °C/s and 1500 °C/s; and, optionally, tempering same at a temperature of less than 300 °C. The aforementioned annealing and cooling operations are performed such that the end band comprises between 1 and 15 % martensite. The invention also relates to the steel band thus formed.</p> |
