extremely well from the standpoint of
hot cracking.
Plate no. 4, however, rated as well
as plate no. 5 in the actual welding
tests (if not in the cast pin tear study)
and enjoys the improvement of impact
strength, and equalization of ductility
in longitudinal and transverse directions, resulting from cerium treatment.
As for deoxidation, the rare-earth
elements are the strongest deoxidizers
that can be added to steel and still
persist as significant residuals to prevent the formation of undesirable oxides and sulfides in, during or near
welding passes. From the standpoint
of the steelmaker rather than the
fabricator, optimum cerium residuals
are obtained by surrounding the teeming stream during casting by an inert
atmosphere—so eager are the rareearth elements to react with oxygen.
Reasonably
priced
construction
steels treated with rare-earth additions
are beginning to appear on the market. Accordingly, the phenomena that
Baker and Emmanuel have investigated, the welding tests conducted by
the latter, and what is known about
the benefits of rare-earth elements in
welding plate, would all seem to be
attaining a significance in welding
technology greater than heretofore.
References
1. Baker, R. G., " M e t a l l u r g i c a l Research
and W e l d i n g P r a c t i c e , " WELDING JOURNAL,
47 (7), Research Suppl., 323-s to 331-s (1968).
2. Boniszewski, T. and W a t k i n s o n , F . ,
Inst. of Welding, S p r i n g Meeting, H a r r o g a t e ( E n g l a n d ) 1964, P a p e r 14.
3. Boniszewski, T. Baker, R. G., J.I.S.I.,
202 (1964) pp 921-28.
4. E m m a n u e l . G. N., and Seng, H. L.,
" A n Investigation of t h e W e l d a b i l i t y of
HY-80 S t e e l . " NObs-84169. F i n a l S u m m a r y ,
R e p o r t No. 564. J a n u a r y 11. 1963
5. Hull, F . C.. "Cast P i n T e a r for Sus-
ceptibility to H o t C r a c k i n g , " WELDING
JOURNAL, 38 (4), Research Suppl., 176-s to
181-s (1959).
6. " E l e c t r o n Microprobe Analysis of Inclusions R e s u l t i n g F r o m R a r e E a r t h Deoxidation of Continuous Cast S t e e l s , " p r i vate r e p o r t to Molybdenum Corporation of
America. BWW-1. October 3. 1968.
7. Meitzner, C. F . , a n d Stout, R. D.,
"Microcracking and Delayed Cracking in
Welded Quenched and T e m p o r e d S t e e l s , "
WELDING JOURNAL, 45 (9), Research Suppl.,
393-s to 400-s (1966).
8. Luyckx, L., Bell. J. R.. McLean, A.,
and K o r c h y n s k y , M., "Sulfide Shape Control in High S t r e n g t h Carbon Steel," Abs t r a c t for 1970 AIME Session on 17-Therm o d y n a m i c s & Kinetics-1, J o u r n a l of Metals. Dec. 1969, 28A.
9. T o p p . N. E.. " T h e C h e m i s t r y of the
R a r e E a r t h E l e m e n t s , " Elsevier P u b l i s h i n g
Company (1965), p. 5.
10. Tucker, H. A.. Coulehan, R. T. a n d
Wilson, W. G., " R a r e - E a r t h Silicide Additions To An Alloy Steel To I n c r e a s e
T o u g h n e s s And D u c t i l i t y , " RI-7153, U.S.
B u r e a u of Mines, J u n e 1968.
11. Engquist, R. D., " J o i n t Effect of
Sulfur a n d R a r e E a r t h Metals on Mechanical P r o p e r t i e s of Cast Complex Low-Alloy
Electric F u r n a c e S t e e l , " P r o c e e d i n g s of
Electric F u r n a c e Conference, Cleveland,
Ohio, 1959, 17, 125-47.
Technical Note: Sulfur and Phosphorus in Low Alloy
Steel Welds Containing Up to 670 Nickel
BY N. KENYON AND A. L. E P S T E I N
Introduction
It has been known since at least
1940 that sulfur and phosphorus can
promote hot cracking and lower
toughness in alloy steel welds. 1 These
damaging effects, however, have become particularly evident in recent
years with the introduction of weldable steels that are capable of retaining
good toughness at high strengths.Investigations of sulfur and phosphorus in welds have usually sought to
define the maximum amounts that can
be tolerated in an alloy composition of
commercial interest. The work described here is somewhat different in
that it examines the influences of sulfur and phosphorus as the level of
another element—in this case, nickel—
is systematically varied.
Experimental Procedure
Materials
The filler metals used contained the
following nominal levels of nickel, sulfur, and phosphorus: N i — 2 % , 4 % ,
N. KENYON is with t h e P a u l D. Merica
Research Laboratory. The International
Nickel Company, Inc., S t e r l i n g F o r e s t ,
Suffern, N.Y., and A. L. E P S T E I N Is a
s t u d e n t a t Rensselaer P o l y t e c h n i c I n s t i t u t e ,
Troy, N.Y.
46-s | J A N U A R Y
1971
and 6%; S—.005%, .010%, and
.020%;P—.008%, .015%, and .020%.
They were fully replicated to give
3 3 or 27 beats. The carbon (0.14%),
silicon
( 0 . 3 % ) , and
manganese
(0.9%) levels were held constant for
all the heats and were selected as
representative for low alloy steel filler
metals. The manganese level was also
chosen so that the values of the manganese/sulfur ratio would always exceed those normally recommended.
The heats of filler metal were airmelted, deoxidized with silicon and
manganese and killed with aluminum.
Rods were extracted from each heat
into Vycor* tubes and swaged and
centerless ground to 0.125 in. diameter for manual gas tungsten-arc welding.
Base Metal
All the welds were made on V 2 in.
thick plate with the following composition ( w t - % ) : Ni-4.0, C-.13,
Mn-.80, Si-.35, S-.007, P-.009 and
Fe-balance.
The 4 % nickel composition was
chosen so that dilution effects from
the plate would be kept to a minimum.
• T r a d e m a r k of Corning Glass W o r k s .
The material for the base metal was
air-melted, deoxidized with silicon and
manganese, and killed with aluminum.
The plates were heat treated at 1600°
F / 1 hr and water quenched.
Welds
One single vee butt weld, 7 in. long,
was made with each filler metal using
the manual gas tungsten-arc process
and a heat input of approximately
70,000 joules/in.
The joint was filled in 10 passes.
The welds were X-radiographed and
transverse slices from the welds were
polished, etched, and examined at
X30 magnification.
The total number of cracks on eight
faces was used as an index of the
cracking tendencies. A standard circular groove test2 was also tried as a
test for crack susceptibility but proved
unsuitable since no cracking occurred
even with the most crack-sensitive
compositions.
Results and Discussion
Effect of Sulfur and Phosphorus on
the Incidence of Cracking
The influence of sulfur and phosphorus on weld metal cracking is
summarized in Figs. 1 and 2. At con-
is
1
10 BUCKS
K005S-
T.012S-
-.OZOS-t—.005S-
-2Ni-
I
-.020S H—.005S-
FILLER WIRE COMPOSITIONS
FILLER WIRE COMPOSITION
Fig. 1—Effect of filler metal composition on weld cracking.
Effect of S at constant P and Ni
H—
-.oizs- -.020SH
— "6Ni —
Fig. 2—Effect of filler metal composition on weld cracking.
Effect of P at constant S and Ni
III
1
1
1
1
1
1
1
1
1
1
1
1
1
CO
n
S
i«
o
o
|
t
1
1
1
30
ss
g
s
F
i2
• /
//
4
20
/
• /
/
-
20
NO cms
- •- —
m CMCKS
/
1
•
•
1
.020
.025
.030
035
.010
.015
-.020
TOTAL AMOUNT S + P «
Fig. 3—Number of weld cracks vs. amount of S-f P for the 4% Ni
filler metals
stant nickel and phosphorus levels,
cracking increased as the sulfur level
increased, the effect being most pronounced at the higher phosphorus
levels—Fig. 1. Very similar trends
were seen when the phosphorus level
was increased while the nickel and
sulfur levels were held constant—Fig.
2. Regression analysis of the number
of cracks vs. composition showed that
within the range studied, sulfur and
phosphorus exerted similar quantitative effects.
At high levels of sulfur and phosphorus the extent of cracking increased with increasing nickel content; but increasing the nickel content
had no effect when the amounts of
sulfur and phosphorus were low.
Crack-free welds were made at the
4% and 6% nickel levels when the
.025
.030
TOTAL A M O U N T S t P *
_ T
.035
Fig. 4—Number of weld cracks vs. amount of S + P
for the 6% Ni filler metals
combined amounts of sulfur and phosphorus were less than approximately
0.020 to 0.025%—Fig. 3 and 4.
In light of these results, some published comments (see, for example,
Lancaster 4 and DMIC Report 172. 5 )
that nickel has an adverse effect cm
cracking appear to be rather arbitrary
and perhaps result from observations
made some years ago when higher
levels of sulfur and phosphorus were
more common. The advantages of increased purity are now widely recognized. Moreover, when a combination
of high strength and higher toughness
is required, low levels of impurity
elements such as sulfur and phosphorus, have been shown to be necessary.2* 6 This is perhaps especially
true for filler metals. 7
Modern refining techniques make
WELDING
these low impurity levels practicable,
and . 0 1 % maximum for sulfur and
phosphorus have proved to be reasonable specifications in high strength,
high toughness steels.2* 6 * 7 These
levels are now being met in commercial filler metals for low alloy steels
with tensile strengths similar to those
involved here, i.e., approximately 130
ksi for the 6% nickel level—Fig. 5.
Conclusions
1. In the low alloy steels examined,
sulfur and phosphorus exerted similar
quantitative effects in promoting weld
cracking.
2. At high levels of sulfur and
phosphorus the extent of cracking increased with nickel content, but the
nickel content had no effect when the
RESEARCH
SUPPLEMENT
| 47-s
amounts of sulfur and phosphorus
were low.
3. Crack-free welds were made with
filler metals containing 6% nickel
when the combined amount of sulfur
and phosphorus did not exceed approximately 0.020%.
140
130
120
References
y
110
/
100
• .005S .008P
• .012S .008P
A .020S .008P
90
I
J_
J_
2
4
•WT. % NICKEL
Fig. 5—Influence of nickel on weld tensile strength
1. Stout, R. D., and Doty, W. D., " W e l d ability of S t e e l s . " W e l d i n g Research Council, 1953, pp. 147-148.
2. Dorschu, K. E., and Lesnewich, A.,
Metals Eng. Q u a r t e r l y , 5, 1965, pp. 20-32.
3. Vagi, J . J., Meister, R. P . , and R a n d all, M. D., " W e l d m e n t E v a l u a t i o n Methods,"
B a t t e l l e Memorial I n s t i t u t e DMIC
R e p o r t 244, 1968.
4. L a n c a s t e r , J. F . , The Metallurgy
of
Welding, Brazing and Soldering,
American
Elsevier, 1965.
5. " B a c k g r o u n d for the Development of
Materials to be Used in H i g h S t r e n g t h
Steel S t r u c t u r a l W e l d m e n t s , " B a t t e l l e Memorial I n s t i t u t e DMIC R e p o r t 172, 1962.
6. P o r t e r , L. F . , Manganello, S. J., D a b kowski, D. S., and Gross, J. H., Metals
E n g . Q u a r t e r l y . 6, 1966, pp. 17-32.
7. Gross. J. H., " T h e New Development
of Steel W e l d m e n t s , " WELDING JOURNAL,
47 (6), Research Suppl., 241-s to 270-s
(1968).
Methods of High-Alloy Weldability Evaluation
Proceedings of a Symposium Sponsored by the
Welding Research Council and Published in November 1970
The Workshop on Methods of Weldability Evaluation was organized and sponsored at the AWS Spring Meeting in Philadelphia, April 30, 1969, by the High
Alloys Committee of the Welding Research Council. The purpose of the workshop
was to exchange information on techniques and special apparatus used for measuring weldability of alloys. Emphasis was on methods, techniques and interpretation of data rather than on specific results. Although solicitation of several
techniques was made, all but one of the submissions involved the Gleeble device
and this one submission was withdrawn before the time of the session.
Initially no written submissions were requested; however, as a result of interest
on the part of participants in the workshop, speakers were asked to prepare
written papers for publication as a WRC monograph.
The papers included in the monograph are:
1. "Development of the R.P.I. Gleeble Equipment"—W. F. Savage (Abstract).
2. "Correlation of Hot Ductility Curves with Cracking During Welding"—
W. Yeniscavich.
3. "Atmosphere Chamber for Test Specimens and Modification of the Dilatometer Control"—K. C. Wu.
4. "Evaluation of Creep During Rapid Heating"—D. Hauser and D. G. Howden.
5. "Multiple Thermal Cycles to Simulate Multipass Welding"—P. W. Holsberg
and W. G. Schreitz.
6. "An Evaluation of the Ductility of Simulated Weld Fusion Zones in Inconel
718"—J. Gordine.
7. "Aerospace Application of the Gleeble"—W. P. Hughes.
8. "Dilatometric Measurements with the Aid of the R.P.I. 'Gleeble Machine' "
— P . F. Martin and C. Rogues.
Methods of High-Alloy Weldability Evaluation is $3.00 a copy. Orders should
be sent to the Welding Research Council, 345 East 47th Street, New York, N. Y.
10017.
48-s | J A N U A R Y
1971