P91钢焊缝蠕变超声检测的敏感参数选择

Ultrasonic sensitivity parameters for creep testing of P91 steel weldments

针对P91钢焊缝蠕变检测问题,对172个蠕变超声检测敏感参数进行了研究。使用2~15MHz频带范围的4种超声探头进行超声检测实验,计算了衰减、声速、噪声功率、频谱特征、非线性特征等参数在P91焊缝热影响区不同位置的测量值。应用归一化聚类分析方法,对上述超声检测参数进行了归类分析,通过与实际P91钢焊缝蠕变金相的对比,确定了第一类检测参数具有作为P91钢焊缝超声蠕变检测敏感参数的潜力。定义了一种蠕变超声检测参数灵敏度的计算方法,利用该方法对第一类检测参数进行了筛选。筛选结果表明：有4种超声检测参数可以作为P91钢焊缝蠕变检测的敏感参数。其中,15MHz探头发射、2MHz探头接收时的非线性参数具有较高的检测灵敏度。研究结果表明,P91钢焊缝蠕变的超声检测中,需要选用合适的传感器组合和选择灵敏度较高的检测参数。

The sensitivities of 172 ultrasonic parameters were studied for creep testing of P91 steel weldments.The ultrasonic testing used frequencies from 2-15 MHz.The parameters,including attenuation,velocity, noise energy, frequency-spectrum parameter, and nonlinear parameter,were calculated along the heat affected zone（HAZ）.All the parameters were classified into 6types using a normalized-cluster analysis.According to metallograph,the first type was suitable for creep testing of P91 weldments.A practical sensitivity concept for ultrasonic creep testing identified 4parameters as more suitable for P91 weldment creep testing.The nonlinear parameter with 15 MHz transmitting and 2 MHz receiving probes was the most sensitive. The results show that suitable probe combinations and sensitivity parameters are very important for P91 weldment creep ultrasonic testing.