| 摘要 |
PURPOSE:To accurately expand a shape memory alloy pipe joint to a target shape by expanding the pipe joint at the temp. below the austenite transformation point and heating the joint up to the austenite transformation completion temp. or above, then cooling the joint right thereafter, at the time of connecting metallic pipes by the above-mentioned pipe joint. CONSTITUTION:The pipe subjected to shape memory to the diameter smaller than the diameter of the pipes to connect the pipe joint is produced at the time of utilizing the shape memory alloy as a pipe joint. A punch of the diameter having a desired expanding rate is inserted into this pipe at the temp. below the austenite transformation point and the pipe is heated in this state to the temp. above the austenite transformation completion temp. and is right thereafter cooled and the punch is removed at the time of expanding the above- mentioned pipe. The expanding of the pipe is executed relatively easily and accurately to the target shape. After the pipes are connected by using such joint, the pipes are heated to the austenite phase region to restore the shape of the joint to the original diameter with the high accuracy of about 95 to 100%. The pipes are thus powerfully joined by the shape memory alloy joint. |
