V-Bendability of Ultrahigh-Strength Low Alloy TRIP-Aided Steel Sheets with Bainitic Ferrite Matrix

Effect of retained austenite characteristics on V-bending in ultrahigh-strength TRIP-aided steel sheets with bainitic ferrite matrix (TBF steel) was investigated for automotive applications. tests were performed a servohydraulic testing machine at processing speed 1 mm/min using 88-degree V-punch (2.0 mm punch radius), V-die (12 die gap, 0.8 shoulder and rectangular specimen (50 length, 5 width, 1.2 thickness). The results are summarized as follows.