Wall thinning rate is an important issue during design of CAP1400 nuclear power plant (NPP) secondary loop. A single-phase flow accelerated corrosion (FAC) test loop was established to simulate the typical working condition of the secondary loop. The wall thinning rate of A335P11 and 20# steel elbow was measured using high precision ultrasonic sensor on the test loop. The results show that elbow part has higher thinning rate than that at straight part, especially at intrados of elbow. Wall thinning rate of 20# steel elbow is about three to four times of that A335P11 steel because of the high contents of Chromium at A335P11. According to the FAC test results it shows that A335P11 could be one of the preferred pipe material of CAP1400 secondary loop.

在CAP1400核电站（NPP）二次回路的设计过程中，壁薄率是一个重要问题。建立了单相流动加速腐蚀（FAC）测试回路，以模拟次级回路的典型工作条件。在测试回路上使用高精度超声波传感器测量A335P11和20＃钢弯头的壁变薄率。结果表明，肘部的稀疏率高于直部，尤其是在肘部。由于A335P11中的铬含量高，因此20＃钢弯头的壁厚稀释率约为A335P11钢的三到四倍。根据FAC测试结果，它表明A335P11可能是CAP1400二次回路的首选管道材料之一。