Cold-rolled steel sheets
440MPa grade Paint Bake-hardenable Cold-rolled Steel for Outer Panels (UNI HITEN™)
Features
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A soft ferrite matrix with a small volume fraction of hard martensite leads to the following high performance:
Low yield strength(YS) equals to 340BH ⇒ Excellent surface-accuracy of pressed-parts (Suppressed surface distortion)
High work and bake-hardenability (WH and BH) ⇒ Superior dent resistance (equal to 440W) - Reduction of outer panel thickness by 0.05mm is possible compared with 340BH by applying UNI HITEN.
- Excellent anti-aging property ⇒ Capable of use in the worm area.
Examples of Product Characteristics
Excellent surface-accuracy and superior dent resistance of outer panel after press-forming and baking
440MPa grade bake-hardenable steel sheets (UNI HITEN) exhibit low YS at the 340BH level and show excellent surface-accuracy after press-forming.
UNI HITHEN can also reduce thickness of outer panels via improved dent resistance by increasing work and bake hardenability.
Anti-aging properties
440MPa grade bake-hardenable steel sheets (UNI HITEN) exhibit excellent anti-aging properties and can be used in the worm area.
Examples of Applicable Automotive Parts
- Suitability for outer body panels required the following characteristics:
・Stretch formability
・Dent resistance
Contributes to reducing thickness of automotive outer panels
Steel sheets for outer panels are used in designation of parts with press-forming. If a steel sheets has high yield strength (YS), the surface distortion of an outer panel is not suppressed after press-forming. On the other hand, an outer panel has low YS after press-forming does not have sufficient dent-resistance, which makes reducing thickness of outer panels difficult. UNI HITHEN contributes to reducing the thickness of outer panels, which has been difficult previously, by achieving both low YS of steel sheets and high YS of outer panels after press-forming due to the high work-hardenability and bake-hardenability achieved by controlling the micro structure of steel sheets.