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由于热疲劳,在压力容器管嘴和环缝中会产生开裂.核设施中的管焊缝、支撑件焊缝以及反应堆池内的平板焊缝会由于裂纹而失效.高周疲劳也会使汽轮机转子中心孔表面产生开裂.磁粉和其它的表面无损检测方法常用来检测表面开口的裂纹,但不能用来确定裂纹深度.裂纹深度可用各种无损检测方法来测定,如超声衍射声程时间法(TOFD)、电压降法和涡流法.TOFD法难于在管嘴焊缝上进行测定,它最适用于评定>5mm的深裂纹.电压降法需要通过其它技术测出裂纹,对裂纹深度的估计精度则在很大程度上取决于裂纹阻档电流的能力.传统的涡流方法较易操作,但测定裂纹深度通常只能测<2mm的浅裂纹.
Cracks can occur in pressure vessel nozzles and gouge due to thermal fatigue Pipe welds in nuclear facilities, support welds, and flat welds in reactor pools can fail due to cracking High cycle fatigue can also cause turbine rotors Cracking of the center hole surface Magnetic particle and other surface non-destructive methods are commonly used to detect cracks in open surfaces but can not be used to determine crack depth, which can be determined using various non-destructive testing methods such as TOFD ), Voltage drop method and eddy current method .TOFD method is difficult to determine the nozzle weld, which is most suitable for the assessment of> 5 mm deep cracks. Voltage drop method requires the use of other techniques to detect cracks, the accuracy of the crack depth estimation Depends to a large extent on the ability of the crack blocking current, the traditional eddy current method is easier to operate, but the determination of the depth of the crack can only usually be measured as shallow cracks <2mm.