Report of Investigations 7933: Source and Control of Nitride Inclusions in Titanium

Details

• Personal Author:
  Anable, Wallace E. ; Henry, Jack L. ; Hill, S. D. ; Schaller, John L.
• Corporate Authors:
  United States. Bureau of Mines
• Description:
  A laboratory- and a pilot plant-scale investigation has been conducted by the Bureau of Mines to examine possible sources of nitride defects in the production of magnesium-reduced titanium sponge. The production of alpha-stabilized nitride inclusions in hot-rolled titanium plate from air contamination of sponge during its manufacture has been experimentally demonstrated. Magnesium- reduced sponge prepared from air-contaminated magnesium or when contaminated by an air leak during reduction, vacuum distillation, or inert gas sweep shows very large variations in nitrogen content. Refractory nitrides, delta tin, and epsilon ti2n have been identified in this sponge. The highest incidence of inclusions resulted from sponge that was reduced by air-contaminated magnesium and from sponge subjected to air contamination during the vacuum distillation cycle and during helium sweep. Air contamination of sponge during the reduction cycle was not nearly as effective in producing inclusions. Tests showed that color and texture may not be reliable criteria for locating defects during sponge inspection. Maintenance of good vacuum-tight integrity, filtration of molten magnesium prior to charging into the reduction retort, and mechanical attrition of sponge to pulverize and disperse nitrides are suggested as practices to lower inclusion incidence in commercial titanium ingots. [Description provided by NIOSH]
• Subjects:
  Metals Occupational Health Safety
• Series:
  Mining Publications
• Subseries:
  Report of Investigations
• ISSN:
  1066-5552 (print)
• Publisher:
  United States. Bureau of Mines
• Document Type:
  Text
• Genre:
  Case Report
• Rights:
  Public Domain
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  ALRC - Albany Research Center
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  60 pdf pages
• Contributor:
  Thompson, Gerald G. ; Abraham, Woodrow L.
• NIOSHTIC Number:
  nn:10009283
• NTIS Accession Number:
  PB-237034
• Citation:
  NTIS: PB 237 034 :48 pages
• Federal Fiscal Year:
  1974
• Peer Reviewed:
  False
• Source Full Name:
  NTIS: PB 237 034
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:de2486403d68c62d9937a7a7bfbb1ff27427a8a5717aa353c33e20cb769fedb9f75bdecdf2d6d02ce815bc6885fe5cf2646c4157f1305dd050627b66b1ac936b
• Download URL:
  https://stacks.cdc.gov/view/cdc/201984/cdc_201984_DS1.pdf
• File Type:
  [PDF - 3.70 MB ]