Purpose and Practical Capabilities of the Metal Magnetic Memory Method

This paper presents the purpose and practical capabilities of metal magnetic memory (MMM) methods. MMM is an advanced Non-destructive Testing (NDT) method developed through accumulation of Self-Magnetic Leakage Field (SMLF) and its distribution analysis in Stress Concentration Zones (SCZs) area. The SCZs is a major source of damages mechanism development and can be detected in express-control mode using specified MMM sensor, scanning devices, and software. It can be performed without require surface preparation and artificial magnetization where it utilizes residual magnetization formed naturally during product fabrication and throughout the operation. MMM method when combined with other NDT methods such as ultrasound dramatically improves inspection result efficiency. Presently, MMM methods are widely employed in base metal and weld joints inspection. For inaccessible objects such as buried pipelines, Non-Contact Magnetometric Diagnostics (NCMD) will be employed with the same fundamentals used by the MMM method. Therefore, it is proposed that MMM is best suited for SCZs detection in feasible diagnosis of equipment and structure and at once enables the assessment of actual stress–strain state to be carried out for all structural elements.