| 摘要 |
PROBLEM TO BE SOLVED: To prevent a crack due to stretch flanging caused in press forming of a steel plate, in particular using a high strength steel plate. SOLUTION: The manufacturing method for a steel plate press formed body is characterized in that a temperature of a steel plate during being formed is set to be >=400 deg.C to <=1,000 deg.C when applying stretch flanging to the steel plate, and the objective steel plate formed body is formed by the method. In such a case a whole steel plate is held in the above temperature region, and the temperature region is set to lie between a blank end and a symmetrical shape of 2d0(λ+1) times the blank end shape, it is preferable that the region lies between a circular or circular arc-shaped blank end subjected to the flanging and a symmetrical shape of 1.1 times the blank end (where d0 denotes a diameter of the blank end,λdenotes a stretch flanging ratio shown by the blank end when it is formed and is expressed as:λ=(d-d0)/d0, d denotes a hole diameter after forming).
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