对TA18钛合金管收缩应变比rCS的测定原理和方法进行了探讨, 同时分析了影响rCS测定的几种因素。结果表明: 取样长度、热处理状态、拉伸速率和伸长率终止条件等因素均对rCS的测定结果有显著影响, 导致rCS测定结果偏低或重现性较差。对于本试验12 mm×0.8 mm的TA18钛合管, 其rCS测定合适的试验条件如下: 试样热处理状态为退火态, 取样长度为150 mm, 两端堵头长度为30 mm, 拉伸速率为1 mm·min-1或2 mm·min-1, 试验终止条件为7%伸长率。

The determination principle and method of contraction strain ratio rCS of TA18 titanium alloy tube were discussed. At the same time, several factors influencing the determination of rCS were analyzed. The results show that factors such as sampling length, heat treatment condition, tensile rate and elongation terminating condition all had significant effects on the testing results of rCS, resulting in lower testing results or poor reproducibility. For the test 12 mm×0.8 mm TA18 titanium alloy tube, the feasible determination conditions of rCS were as follows: the heat treatment condition of specimen was annealing state, the sampling length was 150 mm, the plug length was 30 mm, the tensile rate was 1 mm·min-1 or 2 mm·min-1, and the test terminating elongation was 7%.