Phased Array Ultrasonic Evaluation for Defect Characterization in Aerospace Grade Maraging Steel MDN250 Weldments

Abstract

AbstractQuality and reliability are of great importance in aerospace industry. The factor of safety (FoS) for the aerospace structures is challenging. To meet the challenging FoS, the materials used for pressure vessels are expected to have a very high specific strength. It is important to critically evaluate the internal discontinuities present in a material. Radiographic testing (RT) and ultrasonic testing (UT) have limitations in precise detection and sizing of flaws. Phased array ultrasonic testing (PAUT) technique overcomes the limitations in RT as well as conventional UT. PAUT is an effective method to detect ‘tight cracks’ in the weldments irrespective of orientation in materials and weld joints. This paper deals with the PAUT technique for detection and characterization of flaws in a thin (3.8 mm) pressure vessel weld joints of maraging steel MDN250. This paper demonstrates PAUT superiority over RT and conventional UT. Three case studies are presented to substantiate the claim.KeywordsPAUTNDTRTUT defect characterizationPressure vesselWeld inspectionMaraging steelAerospace structuresQuality