Effects of Mn Content on the Warm Stretch‐Flangeabiliy of C–Si–Mn TRIP‐Aided Steels. Issue 3 (17th February 2017)

• Record Type: Journal Article
• Authors: Sugimoto, Koh‐ichi; Hidaka, Shin‐nosuke; Tanino, Hikaru; Kobayashi, Junya
• Is Part Of: Steel research international. Volume 88:Issue 3(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-02-17
• Subjects: medium Mn TRIP‐aided steel -- retained austenite -- stretch‐flangeability -- warm forming; Steel -- Periodicals; Steel -- Metallurgy -- Periodicals; 669.142
• DOI: 10.1002/srin.201600482
• Languages: English
• ISSNs: 1611-3683

Abstract

Abstract : Effects of Mn content on warm stretch‐flangeability are investigated using 0.2%C–1.5%Si–(1.5–5.0)% Mn transformation‐induced plasticity (TRIP)‐aided sheet steels with annealed martensite matrix. Warm hole‐expansion at 150–250 °C after hole‐punching at 25 °C enhances the stretch‐flangeability of 3 and 5% Mn steels. The warm stretch‐flangeability increases with the Mn content. The superior warm stretch‐flangeability of hole‐punched 5% Mn steel is caused by its large localized ductility on expanding, which results primarily from the stabilization of its large quantity of retained austenite and its fine microstructure. Use of hole‐drilling instead of hole‐punching at 25 °C further increases the stretch‐flangeability and raises the optimum expanding temperature to 250–300 °C. Abstract : Warm stretch‐flangeability of 0.2%C–1.5%Si–(1.5–5.0)%Mn TRIP‐aided sheet steels is investigated. Warm hole‐expansion at T F = 150–250 °C after hole‐punching at 25 °C enhanced the stretch‐flangeability of 5% Mn steel. Use of hole‐drilling instead of the hole‐punching further increased the warm stretch‐flangeability and raised the optimum expanding temperature to T F = 250–300 °C.