Chemical and Metallurgical Analysis of Propellant Storage Vessels.
Abstract
This report covers the examination and metallurgical evaluation of seven tanks after 5 to 8 years storage with N2O4 or ClF5 propellant. The tank materials included cryostretched 301 stainless steel and A-286 stainless steel. The cryostretched 301 stainless steel tanks had positive expulsion devices consisting of ring stiffened diaphragms of 304 stainless steel while the A-286 stainless tanks were unique in utilizing solid state, explosive bonds in place of fusion welds to join the tank components. Leakage by pitting corrosion was found in one positive expulsion 304 stainless steel diaphragm. In addition, deep pitting corrosion was found on the exterior shell of the cryostretched 301 tanks. The interior of the A-286 tanks showed a general, but rather shallow attack, probably from the HN03/HE etching solution used to remove the heavy steel backup mandrels of the explosive bonding process. This general interior attack was somewhat accelerated in or near some of the bonds by the presence of crevices of local highly strained regions. Except for these problems, these two types of tanks performed quite satisfactorily during the extended storage with N2O4 or ClF5.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1979
- Accession Number
- ADA068488
Entities
People
- E. J. King
- H. G. Kammerer
Organizations
- Bell Aircraft Corporation