METALLOGRAPHIC TECHNIQUE FOR THE DEVELOPMENT OF MICROSTRUCTURAL CONSTITUENTS IN GUN STEEL.

Abstract

An investigation was undertaken to develop etching procedures to clearly distinguish certain metallographic features of large forgings. The investigation demonstrates that (1) good microstructure resolution was obtained in untempered martensite using a 2% nital etchant, (2) either 25% sodium bisulfite in water or 4% picral plus hydrochloric acid yielded the best results for both tempered martensite and a duplex structure of tempered martensite and tempered lower bainite, and (3) an aqueous solution of 1% picric acid and 7% sodium tridecylbenzene sulfonate proved highly satisfactory in revealing both the prior austenitic grain boundaries and the macrostructure. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1970
Accession Number
AD0707400

Entities

People

  • Charles J. Nolan
  • Theresa V. Brassard

Tags

DTIC Thesaurus Topics

  • Acids
  • Aqueous Solutions
  • Boundaries
  • Chemical Compounds
  • Grain Boundaries
  • Hydrochloric Acid
  • Martensite
  • Microstructure
  • Picric Acid
  • Steel
  • Sulfonates
  • Water

Fields of Study

  • Materials science

Readers

  • Analytical Chemistry
  • Metallurgy