Improvement Of Jet Engine Descaling Procedure

Item

Title
Improvement Of Jet Engine Descaling Procedure
Date
1952
Index Abstract
Coming Soon
Photo Quality
Complete
Report Number
WADC TR 52-100
Corporate Author
Northrop Aircraft, Inc.
Laboratory
Materials Laboratory
Extent
61
NTRL Accession Number
AD004090
Identifier
AD0004090
AD Number
4090
Access Rights
Notice(s)
Distribution Classification
1
Contract
AF 33(038)-23310
DoD Project
None Given
DoD Task
None Given
DTIC Record Exists
Yes
Distribution Change Authority Correspondence
AFAL LTR
Distribution Change Action Date
1/1/1900
Abstract
X-ray diffraction analysis of the Inconel scale on combustion tube inner liners revealed that it is composed of nickel oxide, the major component, and lesser amounts of chromium oxide and iron oxide. Metallographic examination demonstrated that heavy scale is associated with precipitation, possibly carbides at the grain boundaries, a fact which can explain intergranular corrosion of scaled Inconel in acid solutions. Inconel scale could not be taken off in neutral or alkaline solvents but several acid solutions were found which remove most of the scale without seriously attacking the base metal. Oxidizing pretreatments, particularly with the alkaline permanganate solution in current use by the Air Force, were shown to promote efficient acid pickling. Physical tests of Inconel specimens descaled with the nitric acid-ferric chloride solution revealed that high teiperature pickling (160 deg F) caused a severe loss in tensile strength whereas room temperature pickling caused no appreciable loss in tensile strength. A full scale test of the nitric acid-ferric chloride solution was performed at Norton Air Force Base, San Bernardino, and satisfactory results were achieved.
Report Availability
Full text available
Date Issued
1952-08
Provenance
IIT
Type
report
Format
1 online resource
Creator
Bryan, G. M.
Media
WADCTR52-100.pdf