某压力容器用钢板测厚时出现了厚度显示异常现象，钢板中部厚度均为实际厚度的一半左右。通过采用超声波检测、表面检测、力学性能测试、酸蚀检验和射线检测等方法进行试验，分析了导致钢板厚度显示异常的原因。分析表明，超声波测厚和检测中发现的异常现象是由钢板中低倍组织造成的，是组织反射的结果，而侧弯不合格是由于钢板中心偏析所致。结果可为钢厂加强冶炼工艺、冶炼技术的改进和控制提供借鉴。

While measuring the thickness for a pressure vessel steel plate abnormal display often occurred with the thickness at the plate central being about half of the actual value. A series of tests, including ultrasonic testing, surface inspection, mechanical properties test, acid etch test and radiographic detection method tests, were conducted to analyze the cause of the abnormal display. Results show that, the abnormal phenomenon appearing in ultrasonic thickness test is caused by the plate low times microstructure and is the result of reflecting tissue. And the unqualified lateral bending is due to the segregation of steel plate center. The above-mentioned results may provide reference for the steel mills to strengthen smelting process and smelting technology to improve and control the steel quality.