To provide a steel plate capable of continuous blanking on a commercial scale without causing the reduction in service life of a die, having excellent FB workability and further having excellent formability after FB working.
The steel plate has a composition comprising, by mass, 0.1 to 0.5% C, 0.2 to 1.5% Si and Mn, and Si, P and S controlled into an appropriate range, and comprising one or two kinds selected from 0.0005 to 0.005% Ca and 0.001 to 0.02% rare earth metals so as to satisfy the specified relation with the S content, and has a structure where the average particle diameter of ferrite is 1 to 10 m, the spheroidized rate of carbides is 80% or more, and the amount of carbides in grain boundaries of ferrite defined by the expression of Sgb(%)[={Son/(Son+Sin)}100 (wherein, Son represents the total occupation area of carbides existing in the grain boundaries among the carbides existing in a unit area; and Sin represents the total occupation area of carbides existing in the grains among the carbides existing in the unit area)] is more than 40%. Then, the steel plate can be subjected to continuous blanking on a commercial scale, and acquires superior FB workability and formability after FB working.
NAKAMURA NOBUYUKI
KARIYA FUSAAKI
SETO KAZUHIRO
| JP2006265583A | 2006-10-05 | |||
| JP2000265240A | 2000-09-26 | |||
| JP2000265238A | 2000-09-26 | |||
| JPH09170048A | 1997-06-30 | |||
| JP2005097740A | 2005-04-14 | |||
| JPH08337843A | 1996-12-24 |
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