REPLICATION--NONDESTRUCTIVE ANALYTICAL AND INSPECTION TECHNIQUE

Replicas of surfaces for inspection, material failure and corrosion analysis are useful in cases where the object is difficult to bring into the laboratory. A simple and rapid method of replication is used. Solvent-softened cellulose acetate tape is pressed onto the unprepared surface, allowed to dry, then removed. Examination of such replicas with a scanning electron microscope (SEM), coupled with energy dispersive X-ray (EDX) microanalysis of surface deposits removed by the replica, yields information about failure and corrosion mechanisms. To illustrate the method, replicas were produced and analyzed for several examples of the 18-8 austenitic stainless steel family which were involved in corrosion and failure investigations. Grain boundary and stress crack morphology on a 316 stainless steel tray decking were revealed by the replica method. The as-cast structure of a weld on a section of 316 stainless steel tubing was shown to have little surface structure, while a similar cold worked and solution annealed weld exhibited a finer grain structure than the base metal. A replica of 304 stainless steel tower tray surface showed intergranular corrosion, with the most severe intergranular attack at triple point grain boundary intersections. The structure of the corroded surface of a 316 stainless steel reactor, together with XRF analyses of the corrosion deposits adhering to the replica, suggested that initial intergranular attack had occurred and had progressed to general surface corrosion. Fatigue failure striations were shown in a cast 316L stainless steel rotor by the replica method. Chlorides were detected in cracks in a 316 stainless steel distillation tower tray and by analysis of particulate matter removed from deep in the cracks by the replica. Contaminants from a cooling water leak were also identified among the deposits removed by this replica. /Author/

  • Availability:
  • Supplemental Notes:
    • This paper was presented at the 37th National Fall Conference of the American Society for Nondestructive Testing, Detroit, Michigan, October 3-6, 1977.
  • Corporate Authors:

    American Society for Nondestructive Testing

    914 Chicago Avenue
    Evanston, IL  USA  60202
  • Authors:
    • Scott, R H
    • DeGroot, P B
    • CARON, J
  • Publication Date: 1977-10

Media Info

  • Features: Figures; References;
  • Pagination: p. 45-50
  • Serial:
    • Materials Evaluation
    • Volume: 35
    • Issue Number: 10
    • Publisher: American Society for Nondestructive Testing
    • ISSN: 0025-5327

Subject/Index Terms

Filing Info

  • Accession Number: 00164995
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 23 1977 12:00AM