Tests with 2218-T87 aluminum alloy plate indicate improvements in strength, ductility, fatigue properties, and burst pressure result when one or both of the top and bottom weld beads are removed. There is, however, a drop in yield strength. The consistency of test data is considerably improved by weld bead removal

Hood, D. W.

English

NASA Technical Reports Server

February 1967	 .	 CORRECTED COPY	 Brief 67-10023 
NASA TECH BRIEF I& 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Tests Show That Aluminum Welds Are Improved by Bead Removal 
In welding 1/4- to 1/2-inch thick 2219-T87 alumi-
num alloy plate, top and bottom weld beads are neces-
sary in order to assure full penetration of the metal. It 
was found, however, that the beads caused increased 
stresses at the toes of the welds. 
To eliminate these stresses, tests were run to de-
termine whether the removal of the top and/or bottom 
weld beads would have any effect on the mechanical 
properties of the welded plate. The beads were 
removed by mechanical milling followed by light belt 
sanding. The test results were as follows: 
I. Removal of either top or bottom bead increased 
the ultimate strength (34,000 psi) by 5. 
2. Removal of both beads increased the ultimate 
strength by 10%. 
3. Ductility (7% in 1 inch) increased by 14 when 
the top bead was removed: by 29% when the 
bottom bead was removed. 
4. Ductility was increased by 50/ when both beads 
were removed. 
5. Yield strength followed a reverse trend by becom-
ing approximately 3% lower when the top bead 
was removed, 8% lower when the bottom bead 
was removed, and 11% lower with both beads 
removed. 
Burst tests of as-welded 14-inch diameter 1/4-inch 
tanks resulted in an average burst pressure of 1445 
psi. Pressure increased by 8 with the bottom bead 
removed, 33 with both beads removed, and 56% 
with only the top bead removed. The biaxial type 
loading occurring during burst testing produces maxi-
mum tension stresses at the upper specimen surface.
This accentuated the notch condition at the toe of the 
top weld bead, as indicated by the great magnitude of 
improvement when it was removed. The consistency of 
the test data was considerably improved by weld bead 
removal. 
Fatigue properties were greatly improved by remov-
ing both weld beads. Samples with weld beads failed 
in an average of 545 cycles at a 36,000 psi stress level, 
while samples with both beads removed did not fail 
in 2,000 cycles at the same stress level. 
These tests with 2218-T87 aluminum alloy plate 
indicate improvements in strength, ductility, fatigue 
properties, and burst pressure result when one or both 
of the weld beads are removed. However, the in-
creased advantages must be balanced by the slight 
drop in yield strength. 
Note: 
Inquiries concerning this innovation may be di-
rected to:
Technology I Jtiliial ion Officer 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: B07- 10023 
Patent status: 
No patent action is contemplated by NASA. 
Source: D. W. Hood 
of the Boeing Company 
under contract to 
Marshall Space Flight Center 
(M-FS-1817) 
Category 05 
This document was prepared under the sponsorship or the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19670000023 2020-03-11T20:19:43+00:00Z


Tests show that aluminum welds are improved by bead removal

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