End of ConventionalSingle Process WorkingEnd of Conventional

Single Process Working

Cold Rolled Steel Sheet forHigh Productivity Hot Stamp

Effect

Points

Steel Sheet for High Productivity Hot Stamp, which Enables Continuous Multi-Process Press ‒Press Speed × 5-10 (compared with conventional steel)

Developed Steel with Improved

Hardenability compared with

Conventional Hot Stamp Steel

ConceptConcept

Hardness DistributionHardness Distribution

Hat Channel Formation TestHat Channel Formation Test

Hardness in the Part Has Less VarianceHardness in the Part Has Less Variance

Conveyed to the PressConveyed to the Press

② Our Proposal② Our Proposal

・Manufacturing with multipleprocesses using existing pressmachines (②) is enabled.

・Manufacturing with multipleprocesses using existing pressmachines (②) is enabled.

③③

③Lower Dead Point Retainedfor a Short Time

③Lower Dead Point Retainedfor a Short Time

New Steel Sheet

New Steel Sheet

・Stable strength is obtainedeven with shorter lowerdead point retention time (③).

・Stable strength is obtainedeven with shorter lowerdead point retention time (③).

①Conventional①Conventional

(Lower Dead Point Retention=10 sec)(Lower Dead Point Retention=10 sec)

①ConventionalSteel Sheet

①ConventionalSteel Sheet

Start of FormingStart of Forming

End of FormingEnd of Forming

Natural AirCooling

Natural AirCooling

Time from Start of Forming

Die R AreaDie R Area

Conventional Steel Sheet

Conventional Steel Sheet

(Lower Dead Point Not Retained)(Lower Dead Point Not Retained)

Die R AreaDie R Area

Example of Cross SectionHardness Distribution

Example of Cross SectionHardness Distribution

Distance from the End (mm)Distance from the End (mm)

1st Process

2nd Process

3rd Process

Vickers

Hard

ness