method for manufacturing flat steel products and flat steel product

摘要

The present invention relates to a method for producing flat steels which, after 5% biaxial surface deformation, have a wsa value (1-5) of 0.35 µm, a planar anisotropy of -0.5- + 0 , 5 and nanohardness h of 0.1 to 3.0 gpa from the surface to depth of 200 µm. plate consisting of (in% by weight) 0.0003-0.050% of c, 0.0001-0.20% of itself, 0.01-1.5% of mn, 0.001-0.10% of p, 0 0.0005% -0.030% s, 0.001-0.12% ai, 0.0001-0.01% n, in each case optionally 0.001-0.15% ti, 0.0001-0.05% nb = 0.005% b = 0.15% cu = 0.15% cr = 0.15% ni = 0.10% mo e = 0.05% sn The remainder consisting of Fe and impurities is: heated to the bzt plate removal temperature of 1200-1270 ° C; rough-rolled laminate with 80-90% thickness reduction; hot-rolled with 85-95% thickness reduction and final temperature of 850-950 ° c, 95-99.5% total deformation degree and ¿df thickness reduction in last hot-rolling passage of 1-25 %, to produce finished flat steel of 3-5 mm thickness, cooled to 4-30 k / s rate for ht coil temperature 620-780 ° c. Pickling is cold rolled with a total deformation of 70-90% and annealed with recrystallization at 65-900 ° C. bzt, glz, ¿df and ht meeting the condition of -0,529653 * q + 0,944372 * ht_t + 0,711559 * ¿df_j -0,1889459, where bzt is in ° c, glz is in min, ht is in ° c and df is in% and for q = ((bzt / glz) -5,553 ° c / min) / (1,777 ° c / min), the following applies ht_t = (ht-728,13 ° c) / 42.300 ° c and df_t = (df12.43384%) / 2.306328%.