COLD ROLLED STEEL SHEET FOR ULTRA-DEEP DRAWING EXCELLENT IN ELONGATION FLANGING PROPERTY AND ITS PRODUCTION

摘要

PURPOSE: To obtain a cold rolled steel sheet combining elongation flanging properties and ultra-deep drawability and suitable for the integral molding of automotive panel parts in particular. ;CONSTITUTION: This steel sheet has a compsn. contg. ≤0.0034% C, ≤0.1% Si, ≤0.3% Mn, 0.005 to 0.10% P, ≤0.0034% S, ≤0.005% N and 0.002 to 0.1% Al and furthermore contg. Ti and Nb in the ranges where Ti is ≥0.025% and (4C+1.5S+3.4N) to 0.1% and Nb is 3.5C to 0.025%, and the balance substantially Fe, and in which the amt. of phosphides having ≥0.1μm diameter is suppressed to ≤0.05%. In this way, the cold rolled steel sheet suitable for the integral molding of composite parts can be obtd.;COPYRIGHT: (C)1994,JPO