18%Ni マルエージ鋼のプレス成形性に対する変態誘起塑性の効果

概要

論文の詳細を見る
The effect of transformation induced plasticity on the press formability has been experimentally investigated at various temperatures and strain rates for 18% Ni maraging steels. The results obtained are as follows. (1) The best formability is obtained at 225℃ (498K) for 210kg/mm^2 class maraging steel and 275℃ (548K) for 245kg/mm^2 class one under various formability tests as deep-drawing, stretching, burring and bending. (2) The forming limits of the formability tests mentioned above agree relatively well with the values from the Forming Limit Diagram (F.L.D.) which represents the forming limit at two dimensional stress states. However, when the work-piece is subject to strain gradient or is restricted by tool as in the case of burring test, the forming limit is higher than the value from the F.L.D. (3) The effect of strain rate on the forming limit is not recognized experimentally in the almost all stress states expect for uniaxial stress state in the F.L.D. This phenomenon depends on that the heat of deformation transfers to the tool rapidly, when the work-piece is in contact with the tool.
社団法人日本鉄鋼協会の論文
1979-07-01