A METHOD FOR MANUFACTURING COLD ROLLED STEEL SHEET FOR DEEP DRAWING HAVING EXCELLENT PRESS FORMABILITY

摘要

The present invention mainly relates to a method for producing a cold-rolled steel sheet to be used for deep drawing in, automobile outer plate. ; The present invention in weight%, C: 0.0005 ~ 0.003%, S: 0.003 ~ 0.025%, Al: 0.01 ~ 0.08%, N: 0.004% or less, P: 0.01 ~ 0.10%, Cu: 0.01 ~ 0.2%, remainder Fe and the other is composed of incidental impurities, of the components of Cu and S is satisfied 0.5 × Cu (%) / S (%) = 1 ~ 10, also one of the components C, Mn, P, Cu and Si is Q = 20-100 [However, Q = 90 C (%) + 225 Mn (%) + 120 P (%) + 460 Cu (%) - 100 Si (%)] satisfying the steel slab to 1150 ~ 1300 ℃ in steps that reheating; The finish reheating steel slabs to the US recrystallization temperature (Tnr) per rolling pass the commencement of the finish rolling at less than the reduction amount of deformation of 35% or more rolling conditions paths that have more than pass the hot rolling, and then step winding at 600 ~ 700 ℃; Cold rolling the hot-rolled sheet with a reduction ratio of the take-up of 50-90%; It comprises; and a step of continuous annealing the cold-rolled steel sheet from 500 ~ 900 ℃. ; According to the present invention while having the intensity of 270 ~ 310MPa tensile strength can be produced to facilitate the cold-rolled steel sheet having excellent deep drawing formability than conventional deep drawing steel sheet. ; Deep drawing, automotive steel, texture, plastic strain ratio, non-recrystallization temperature