Ultrasonic Velocity Inspection to Ductile iron
Material Quality and Nodularity
Our foundry is using the Dakota ultrasonic
velocity tester to inspect the quality and nodularity of ductile
iron castings. This method could inspect material quality to large
quantity of iron and steel castings.
According to our experience, if the velocity is high, then the
material and nodularity is good, otherwise, the material quality
will be bad or unqualified.
Higher than 5600 m/s, the rate of spheroidization will be higher
than 90%, material is very good.
Lower than 5500 m/s, the rate of spheroidization will not be good,
the rate may be lower than 75%.
Between 5500 to 5600 m/s, the rate of spheroidization will be good,
qualified. The rate will be 75% to 90%.
However, there are some key operation techniques to get the accurate
inspection result. Such as:
1. The thickness of the inspection point should be accurate and
2. If the surface is not clean and flat, it will need some grinding,
otherwise, the result will be 10 to 50 m/s lower than the correct