| 摘要 |
A process for improving the strength characteristics of a wire composed of an austenitic metal alloy selected from the group consisting of stainless steel alloys of the AISI 200 and 300 series and non-stainless steel alloys containing iron, manganese, chromium, and carbon, said alloy having an Md temperature of no higher than about 100 DEG C and an Ms temperature of no higher than about minus 100 DEG C, comprising the following steps: (a) deforming the wire at a strain of at least about 10 percent and at a temperature in the range of about Md minus 50 DEG C to about Md plus 50 DEG C, said Md temperature being that of the alloy undergoing deformation, in such a manner that the wire has a martensite phase of no greater than about 10 percent by volume and an austenite phase of at least about 90 percent by volume and a yield strength in the range of about 130,000 psi to about 230,000 psi; (b) cooling the wire to a temperature no higher than about minus 75 DEG C; and (c) drawing the cooled wire through a die under back-tension (i) wherein the back-tension on said wire just prior to the entry of the wire into the die is at least about 75,000 psi and (ii) whereby the cross-sectional area of the wire is reduced by a percentage in the range of about 7 percent to about 25 percent, in such a manner that the wire has a martensite phase of at least about 50 percent by volume and an austenite phase of at least about 10 percent by volume. |
