Countermeasures Against Forming Defects and Techniques to Improve Formability for High Strength Steel Sheets
Springback is one of the most difficult problems in applying high strength steel sheets to automotive body parts.The mechanism of springback behavior classified by the phenomenon and countermeasures based on each mechanism were reported.It was made clear that section opening of member parts was reduced by crash forming and wall tension control.And torsion and camber of complicated shape parts were possible to decrease by planer stress control using the developed analytical methods of CAE.Basic concept of countermeasure for springback is expected to design the part high rigidity at first,utilize the stress control methods and minimize the compensation of die tools.Another problem of high strength steel in forming process is edge fracture at stretch flange area.Although the factor of crack initiation is caused by complicated procedure due to various cutting conditions and ununiform distribution of stress and strain,we could evaluate this phenomenon by developing edge fracture test for practical automotive body parts and new side bending test method.From using these evaluation methods,we propose to design shapes for each high strength steel and proper conditions of the cutting edge for preventing edge fracture of stretch flange area.
Sheet metal forming High strength steel sheets Springback Edge fracture Finite element methods
Tohru Yoshida Koichi Sato Eiji Isogai Jun Nitta Hiroshi Yoshida
Steel Research Laboratories,Nippon Steel & Sumitomo Metal Corporation,20-1 Shintomi,Futtsu,Chiba,Jap Nagoya R&D Lab.,Nippon Steel & Sumitomo Metal Corporation,5-3 Tokai-cho,Tokai,Aichi,Japan Hirohata R&D Lab.,Nippon Steel & Sumitomo Metal Corporation,1 Fuji-cho,Hirohata-ku,Himeji,Hyogo,Japa
国际会议
The 2nd International Symposium on Automobile Steel (第二届汽车用钢生产及应用技术国际研讨会)
鞍山
英文
29-36
2013-05-21（万方平台首次上网日期，不代表论文的发表时间）