Ultra-deep-draw Ti-IF steel cold rolling and annealing process

Abstract

The invention relates to an ultra-deep-draw Ti-IF steel cold rolling and annealing process. A steel plate blank comprises the following chemical components in percentage by weight: less than or equal to 0.005% of C, less than or equal to 0.2% of Mn, less than or equal to 0.01% of P, less than or equal to 0.008% of S, more than or equal to 0.015% of Alt, 0.04-0.064% of Ti, less than or equal to 0.006% of N and balance of Fe and microimpurities which can not be detected; five-pass cold rolling is adopted in a cold rolling process, and the total rolling reduction of the five-pass cold rolling is 75-85%; inlet rolling speed and outlet rolling speed are respectively 260KN and 29KN; and an anneal process comprises two-stage warming, wherein heating rates are respectively 70-85 DEG C / h and 30-45 DEG C / h, annealing temperature is 680-720 DEG C, holding time is 8-15 hours, then three-stage cooling is adopted, cooling rates are respectively 25-35 DEG C / h, 35-45 DEG C / h, 15-25 DEG C / h, and finally cooling to room temperature is carried out. The ultra-deep-draw Ti-IF steel cold rolling and annealing process provided by the invention has the advantages that the tensile strength after the process is carried out is up to 290-320MPa, the yield strength is 100-160MPa, the strain hardening index is more than or equal to 0.25, and the planar aeolotropy degree is less than or equal to 0.60.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and relates to an ultra-deep drawing Ti-IF steel cold rolling and annealing process. Background technique [0002] Ultra-low carbon interstitial atom-free steel (IF steel) is characterized by very low carbon and nitrogen content, and Ti and Nb are added to the steel to form C and N compounds of Ti and Nb, so that carbon and nitrogen interstitial atoms in the steel can be eliminated , which has superior deep drawing performance. The {111} plane texture formed in the cold rolling process of IF steel undergoes a process of dislocation activation, which increases the stored energy of {111}. Because the dislocation storage rate is related to the grain orientation, it has a high deformation storage energy. During the annealing process, these subgrains (or grains) will preferentially recover and nucleate in situ, and then annex the grains of other orientations. Grains further strengthen the {111} su...

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Problems solved by technology

The Chinese invention patent of 201110393370.2 discloses a titanium-containing IF steel and an annealing process. The annealing process described in this patent is not suitable for large-scale industrial batch production, and is only suitable for annealing small samples to obtain excellent properties

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