Abstract
The two separate projects described both use ultrasonic beams for the interior inspection of steel, particularly in the billet stage. Progress in both areas has been made, and work continues. The inspection of hot steel for central pipe and segregation has led to the development of a machine for works trials based upon the use of rolling contact under pressure. The primary problems here are establishing coupling, and avoiding overheating the ultrasonic probes without drastically cooling the steel. Correlation is required to be established with cold ultrasonic inspection and sulphur printing and macro-etching. The second project is intended to provide for the ultrasonic assessment of background or general inclusion content over a substantial volume of steel. The detection of individual inclusions above a certain minimum size is also envisaged and is already an established technique. The immediate aim has been to establish correlation between optical measurements using the QTM, so that confidence can be established. Considerable progress has been made towards that end. Problems have been defined in connexion with the choice of ultrasonic probes and conditions, the actual selection of volumes sampled, and the statistical variations of the optical measurements. It is expected that these various factors will be properly evaluated and controlled.
Get full access to this article
View all access options for this article.