为了准确检测入厂原材料钛合金的规定残余延伸强度, 实现程序自动化控制, 依据GB/T 228-2002中的相关规定, 采用卸荷法测定了ZTC4钛合金的规定残余延伸强度, 研究了循环次数和保荷时间这两个参数对检测结果的影响, 探索出了适合钛合金材料测定规定残余延伸强度的试验参数。结果表明: 选择循环次数与保荷时间之比即单位时间的循环次数作为表征规定残余延伸强度的参数是合理的, 合理的试验参数为保荷时间10~12 s, 循环次数4～6次, 与GB/T 228-2002规定一致;当单位时间的循环次数在0.33～0.60范围内时, ZTC4钛合金的规定残余延伸强度最小, 可作为材料的最大许用应力, 其工作状态下的应力不能超过此限, 否则, 工件就可能会发生破坏。

In order to accurately detect the permanent set strength of incoming titanium alloy raw materials and realize programmed automation control test, the permanent set strength of ZTC4 titanium alloy was tested by unloading method according to the relevant regulations from GB/T 228-2002. Affecting factors such as cycle numbers and duration time on the test results were studied and appropriate test parameters for titanium alloy were gained. The results show that selecting the ratio of cycle numbers and duration time that was the cycle numbers in unit time as parameter to characterize the permanent set strength of titanium alloy was reasonable, and the appropriate duration time was 10-12 s and the appropriate cycle numbers was 4-6 times that was corresponded to the regulations of GB/T 228-2002. When the cycle numbers in unit time were in the range of 0.33-0.60, the tested permanent set strength of ZTC4 titanium alloy was minimum, and it can be regarded as the maximum allowable stress. If the working stress exceeded this limit, the work piece would failure.