STRESS-CORROSION CRACK DETECTION AND CHARACTERIZATION USING ULTRASOUND

STRESS-CORROSION CRACKING IS A COMPLICATED MECHANISM INVOLVING (1) SUSTAINED SURFACE TENSILE STRESSES, (2) AN ALLOY AND TEMPER SUSCEPTIBLE TO THIS PHENOMENON AND (3) A CORROSIVE ATMOSPHERE. DESCRIBED IS THE DEVELOPMENT OF A NONDESTRUCTIVE TEST TECHNIQUE FOLLOWING THE OCCURRENCE OF A STRESS-CORROSION FAILURE IN A RING SUPPORT STRUCTURE OF 7075-T6. CONFIGURATION OF THE PART AND CONCEALMENT OF THE AREA OF SURFACE TENSILE STRESSES UNDER A GLASS-RESIN STRUCTURE DICTATED THAT A SHEAR WAVE TECHNIQUE BE USED TO DETECT AND CHARACTERIZE THE STRESS-CORROSION CRACKS. TEST FREQUENCIES, TYPES OF SEARCH UNIT AND VARIOUS COUPLANTS WERE INVESTIGATED TO DETERMINE OPTIMUM SENSITIVITY AND RESOLUTION WITH MINIMUM ATTENUATION. TEST TECHNIQUES WERE DEVELOPED WITH CONCERN FOR LOCATION OF PROBE, ANGLE OF REFRACTED WAVE AND AMPLITUDE OF DISCONTINUITY INDICATION. TO SIMULATE DISCONTINUITIES, MACHINED STANDARDS WITH AREAS RELATED TO CRACKS OF VARIOUS LOCATIONS, SIZES, DEPTH AND ANGLES WERE EVALUATED. CHARACTERIZATION WAS FINALLY OPTIMIZED THROUGH DEVELOPMENT OF STANDARDS WITH INDUCED STRESS-CORROSION CRACKS OF VARIOUS SIZES, LOCATIONS, DEPTHS AND ANGLES PROPAGATED BY SUBMITTING SECTIONS OF THE PART TO ACIDIFIED SALT SPRAY WHILE UNDER A RESIDUAL TENSILE STRESS OF 80 PERCENT OF THE YIELD STRESS. INFORMATION WAS CORRELATED USING DATA FROM BOTH THE ULTRASONIC AND METALLOGRAPHIC EVALUATION OF THESE SPECIMENS. /AUTHOR/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00255327
• Supplemental Notes:
  • Vol 27, No 6, PP 135-139, 12 FIG
• Authors:
  • Weil, B L
• Publication Date: 1969-6

Media Info

• Serial:
  • Materials Evaluation
  • Publisher: American Society for Nondestructive Testing
  • ISSN: 0025-5327

Subject/Index Terms

• TRT Terms: Alloys; Corrosion resistance; Cracking; Detection and identification; Detectors; Metallography; Metals; Nondestructive tests; Salt fog tests; Stress corrosion; Stresses; Tension; Test procedures; Ultrasonic tests
• Uncontrolled Terms: Tensile stress
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00216857
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 2 1994 12:00AM