| 摘要 |
PURPOSE:To provide a partial form memory effect to a high Mn steel by adding a specified amt. of Si, Ni or Cr to the steel and regulating the total amt. of the additive and Mn to raise the Ms point to room temp. or above and lower the As point. CONSTITUTION:To a high Mn steel is added Si 1.0-5.5%, Ni 1.0-4.7% or Cr 1.0-4.7%, and the total amt. of the added element and Mn is regulated to 17.7- 21.5%. After applying tensile or compressive stress to the steel, an assembled structure is constructed. When this constructing material is heated to the As point or above and cooled to the Ms point or below, the final length is perfectly returned to the length before the heating even if a plastic deformation strain is applied before the heating, thus obtaining such a partial form memory effect that the temp. history curve of elongation returns to 0 point. Accordingly, characteristics such as enhanced bolt holding power to a structure are provided. |
