The penetration ability is large. For example, the effective detection depth in steel can reach more than 1 m ;  For planar defects such as cracks , interlayers , etc., the flaw detection sensitivity is high, and can determine the depth and relative size of the defect ;  The equipment is light , safe to operate and easy to realize automatic inspection .  The disadvantages are: it is not easy to inspect the workpiece with complex shape , the surface to be inspected is required to have a certain finish , and the coupling agent is required to fill the gap between the probe and the surface to ensure adequate acoustic coupling.  For some coarse-grained castings and welds, it is difficult to apply because it is easy to produce chaotic reflection waves.  In addition, ultrasound testing also requires experienced inspectors to operate and judge the results of the test. 

Ultrasonic Testing ASTM A-253MA / UNS S30815 stainless steel sheets .