METHOD FOR PRODUCING LOW YIELD RATIO HIGH TITANIUM BASE STEEL PLATE EXCELLENT IN BARE ATMOSPHERE CORROSION RESISTANCE

摘要

PROBLEM TO BE SOLVED: To provide a useful method for producing such a slow yield ratio high Ti base steel plate, as which a good atmosphere corrosion resistance is achieved by adding Ti in comparatively high content and in spite of addition of Ti, the low yield ratio can be realized by restraining the precipitation of TiC after transformation and if necessary, the excellent weldability can be exhibited.;SOLUTION: A steel material containing ≤0.2% C, 0.1-1% Si, ≤2.5% (excluding 0%) Mn, 0.025-0.5% Ti and ≤0.01% (excluding 0%) N, is used. Then, a rolling reduction is applied to this steel material at ≥30% the accumulated value so that the surface temperature is in the temperature range of ±50°C of a temperature T(°C) regulated by the following equation (1). T(°C)=1500+([Ti]-[N]×3.4)+800-the plate thickness (mm) ...(1) Wherein, [Ti] and [N] are contents (mass%) of Ti and N, respectively and when [Ti] is 0.1%, [Ti]=0.1%.;COPYRIGHT: (C)2001,JPO