Accession Number:

AD0643401

Title:

AN ELECTRON OPTICAL SURVEY OF IRON OXIDE FILMS PRODUCED IN H2O, 1,5% LIOH, AND LIOH/EDTA (PH 11) SOLUTIONS AT 316 deg. C

Descriptive Note:

Interim rept.

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

Report Date:

1966-09-29

Pagination or Media Count:

21.0

Abstract:

In the exploration of steel corrosion mechanisms pertinent to steam power generation, LiOH has been investigated as an alkalizing agent to form protective oxide films on boiler walls. Steel capsules treated in three different ways, a with H2O, b with 1.5 LiOH solution, and cwith LiOHEDTA pH 11 at 316C, formed films which, in the initial stages of development, were shown to be Fe3O4. However, the crystallite size, the degree of orientation, and the film uniformity and continuity, determined by electron microscopy and diffraction, varied with the method and length of treatment. The film formed by distilled water showed small 1000 to 2000 A, oriented crystals with sharply delineated areas of growth. When the LiOH solution was used in the treatment, larger crystals were formed but flaws were still noticeable after 24 hours. With the LiOHEDTA solution, the growth of the crystals was very rapid, forming a thick, coherent film on the metal, which should offer excellent protection against corrosion.

Subject Categories:

  • Physical Chemistry
  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE