When talking about production process of seamless steel pipe, the first step would be billet inspection. Then here is the question: how could we guarantee the high quality for this step? This would depend on the billet inspection techniques.

Here is the sketch map for the techniques. There are six main aspects: eddy current technique, flux leakage technique, micro wave technique, optical technique, thermal technique, ultrasonic technique. With totally inspection, we’ll make sure the first step’s safety for seamless steel pipe. For the details, we can take eddy current technique for example. The application of eddy currents to continuously cast billet inspection makes it necessary to consider an inspection interval or pitch of the order of 1 mm to 2 mm to cater for the pinhole type defects. As for more details, we will discuss in next essay.