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Title: On the measurement of austenite in supermartensitic stainless steel by X-ray diffraction

Sections of a 13Cr supermartensitic stainless steel were investigated to determine the optimum sample preparation for measurement of the austenite content by X-ray diffraction. The surface of several samples was mechanically ground or polished using media of grit sizes in the range 1–120 μm. The strained surface layer was afterwards removed stepwise by electropolishing, and the austenite content measured at each step. It was found that any level of mechanical grinding or polishing results in a reduction of the measured austenite fraction relative to the true bulk value, and that coarser grinding media impart greater damage and greater reduction in the measured austenite content. The results thus highlight the importance of the electropolishing step in preparation of such samples, but suggest that the American Society for Testing and Materials standard E975-03 substantially overestimates the amount of material which needs to be removed to recover the true “bulk” content. - Highlights: • Quantitative Rietveld analysis of austenite/martensite ratio in supermartensitic stainless steels • Critical evaluation of sample preparation for residual austenite measurements by X-ray diffraction • Highlighting of the importance of electropolishing as a final preparation step.
Authors:
 [1] ; ;  [1] ;  [2]
  1. Department of Materials Science and Engineering, Norwegian University of Science and Technology, Trondheim (Norway)
  2. Statoil, Stavanger (Norway)
Publication Date:
OSTI Identifier:
22476021
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Characterization; Journal Volume: 99; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AUSTENITE; CHROMIUM COMPOUNDS; ELECTROPOLISHING; LAYERS; MARTENSITE; MARTENSITIC STEELS; REDUCTION; SAMPLE PREPARATION; STAINLESS STEELS; STRAINS; SURFACES; TESTING; X-RAY DIFFRACTION