CA1052135A - Wrought filler metal for welding highly-castable, oxidation resistant, nickel-containing alloys - Google Patents

Abstract

Abstract of the Disclosure A hot-workable, cold-workable alloy particularly useful as a wrought filler metal contains up to about 0.2% carbon, up to about 4.5% (preferably up to about 2%) manganese, about 18% to 30% (preferably about 19% to about 24%) chromium, up to about 1.5% silicon, about 5%
to about 50% (preferably about 15% to about 25%) iron, about 0.1% to about 1% (preferably about 0.12% to about 0.4%) boron, about 3% to about 9% (preferably about 4%
to about 8%) molybdenum, and the balance, preferably at least about 30% nickel.

Description

S'~ ~35 The present invention relates to nickel-base alloy~ -having workability and weldability and, more particularly, ~o wrought filler wire ~or use in the general welding of high s nickel alloys and inert gas shielded-arc welding of highly castable, oxidation-resistant, nickel-base alloys.
~ ; There is a need in the art to weld oxidation-resistant ; nickel-base alloys under a variety of industrial conditions.
As a filler wire, or example, the alloy should be suitable for welding ~ith all major arc-welding processes, e.g., gas ~ ` 10 - tungsten-arc, gas metal-arc, submerged-arc, and be capabla of ; producing souna welded joints under conditions imposing severe ~- restraint and difficult paxameters for both thin and heavy j~ i section welds. It is also desirable that the alloy be suitable ~ -for use as a core wire in a covered electrode.
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While sound welds may be made in ~ny instan~es;.w:ith:
~ ~ matching composition filler material, industry prefers that i~` contlnuous,~hiqh deposition-rate~welding processea be employed `~
;~ said processes requiring however, that the filler metal be -readily workable to forms such as wire. Cast filler material~
for high production~rate welding processes are not economically ~, fea~ible and it i~ essential that the filler ma~erial be at least hot workable in order to afford the ad~antages of con~
tinuou~ welding processes. More advantageously, the alloy should be cold workable, allowing the alloy to be formed to thin cro3s-~ections, e.g., wire, which is the form pre- ;~
dominantly u~ed in continuous high depo~ition-rate welding ~, proce3~es. `:.
One particular application requixin~ a wrought filler `~
metal i~ for the welding of a hiqhly castable, oxidation~
`~' - 30 resistan~, nickel-base alloy comprising nominally 21~ chromium, -` 19% iron, 6~ molybdenum, 3~ silicon and 0.3% boron.~ ~his; - ~;

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alloy is particularly suitable for the conventional casting of components having an intricate design and is also weldable, allowing fabrication of several small components into one large unit and for repairing of casting defects or even service damage. ~owever, the alloy is not workable nor, insofar as we are aware are other suitable wrought filler materials available for weldin~ this alloy.
It has now been discovered that sound welds, which ;~
are free from cracking and poroslty and which have osidation resistance equivalent to that of the base alloy, can be made under conditions imposing severe res~raint by welding with a - specially formulated wrou~ht filler wire.
It is an object of the invention to provide a wrought filler wire suitable for welding nickel-base alloys.
The invention also contemplates an alloy composition ; having a combination of characteristics including excellent workability and weldability Other objects and advantaqes will become apparent from the following description.
` 20 Generally-speaking, the present invention contemplateg .
a wrought filler alloy containin~ (by weight) up to about 0.2%
carbon, up to about 4.5~ manganese, up to about 1.5% silicon, from about 18% eo about 30~ chromium, from about 5% to about 50% iron, from about 0.1% to about 1% boron, from about 3~ to about 9% molybdenum, and`the balance essentially nickel. As will be understood by those skilled in the art, the use`of the e~pression "ba}ance essentially" in referring to the nickel content of the alloys does not exclude the presence of other elements commonly present as incidental constituents and impurities.

-2 ~S'~3S
In carryin~ the inventio~l into practice, it is pre-ferred that the wrought filler a:Lloy contain up to about 0.1~ carbon, up to about 2% manganese, up to about 1% ~ilicon, from about 19% to about 24~ chrornium, from about 15% to about 25% iron~ ~rom about 0.12~ to about 0.4% boron, from about 4%
to about 8% molybdenum, and the balance, in an amount of at least about 30~, essentially nickel.
A still more preferred wrought filler alloy contains~ ;
from about 0.003% to abbut 0.~6% carbon, up to about 1%
manganese, up to about 0.4~ silicon, from about 20~ to about 24% chromiumt from about 17% to about 23~ iron, from about 0.15% to about 0.4g boron, from about 5% to about 7% molybdenu~
and the balance, in an amount o at least about 30%, essentially nickel.
Carbon has been found to ha~e a detrimental effect ~n ,, the workability of the alloy and must be maintained at levels below about Q.2~, and preferably only up to about 0.1%, to achieve the desired working characteristics of this alloy Advantageously, it is preferred that the carbon be maintalned - 20 from about 0.003~ to about 0.06% in the interests of work~
` ability. `
~:
Manganese may be maintained in the alloy at levels up to about 4.5%, but in the interest of stress-rupture life, ~:
manganese!should be limited to levels up to about 2% and preferably, up to about 1%. Silicon has a detrimental effect on~he workability of the alloy and should be maintained at 1evels not above about l.S% and preferably not in excess of about 1%. Silicon also had a detrimental effect on the oxida-. . . ~
tion resistance of the alloy; howevex, the presence of silicon up to about 0.4~ is desirable to produce an alloy having both excellent oxidation resistance and workability. I
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Chromium is essential in the alloy for oxidation resistance at elevated temperatures. Chromium also affects the weldability of the alloy and should be maintained above about 18% for this purpose. While chromium levels up to about 28.4~ chromium have produced satisfactory-welds, the upper limit for chromium is about 30% in order to insure freedom from the formation of deleterious sigma phase. It would be expected that alloys approaching the upper limit of about 30% chromium would start to exhibit edge cracking in hot working and would be more difficult to cold work. It is preferred that a compositional range of about 19~ to about 24% be employed.
Iron, at levels below about 5% are not weldable as they exhibit severe weld cracking. The upper limit for iron is dictated by its effect on the oxidation resistance of the alloy and should be maintained below about 50~ for this purpose.
- A desirable combination of weldability and oxidation-resistance properties are achieved at iron levels from about 15~ to about . . . . .
` 25%.
Boron at levels below about 0.1% has a detrimental effect on both hot workability and weldability. Alloys con-taining boron up to abou~ l~ are hot workable; however, in order to achieve an ~lloy having hot workability and cold workability properties, it is preferred that the boron be maintained in the range from about 0.12~ to about 0.4%. Boron also affeats the oxidation resistance of the alloy and for this purpose should be maintained in the range from about 0.12%
to about 0.4%.

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It is believed that molybdenum imparts a tolerance for elements, e.~., boron, which mi~ht detrimentally affect the weldability characteristics of the alloy composition.
Molybdenum should be maintained within the ran~e of about 3%
to about 9~, preferably from about 4% to about 8~ and most advantageously, from about 5% to about 7%. Molybdenum levels at the lower part of the range of 3% result in an alloy having a re~uced oxidation resistance and the upper limit of 9~ is dictated by its effect on the decrea~ed workability of the alloy and the onset of weld cracking.
Nickel contributes to the elevated tempexature oxida-tion resistance of the alloy and suppresses the embrittling si~na-forming tendencies of silicon, molybdenum and chromium.
While the nickel composition may vary widely, depending on the percenta~es of the other elements, it is desirable that nickel be present in an amount of at least ahout 30~ to achieve ; ~
a desired combinatlon of properties. ~ ~ ;
Aluminum or other suitable deoxidation elements are desirably added to the alloy melt; an aluminum level of up to ;;
about 0.1~ has been found to be quite satisfactory. Levels significantly above say, 0.15% for example, 0.5%, should be -avoided however, since such levels tend to detract from the `~
workability of tha alloy. Consi~tent with good steel-making practice, other additive3, such as desulfurizing agents and the like, may also be added to the melt. Phosphorus and sulfur may have a detrimental influence on wor~ability and weldability and should be maintained at levels less than about 0.04%.
For the purpose of giving those ~kille~ in the art a ~
better under~tandinq of the invention, the following examples ~ `
are given: ~`
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, lOS~135 EXAMPLE I

To demonstrate the excellent workability and weld-ability of al1Oys in this invention, various alloy composi-tions were prepared. As shown in Table I, Alloy Nos. 1-22 are within the invention and ~lloy Nos. ~-L are out~ide the scope of this invention. All alloys were prepared by air-induction melting at a temperature of about 2900F. a charge consisting of electrolytic nickel, low carbon chromium and electrolytic iron. The temperature of the melt was then reduced to about 2800F. and carbon added as high carbon (10%~
chromium metal, followed by electrolytic mangane~e, metallic silicon, molybdenum pellets, rod aluminum and a nickel-boron alloy (about 16% boron). The melts were poured at about 2750F~ into four-inch square cross-section cast-iron molds.
The ingots were soaked f or about four hours at about 2100~F., hot-rolled to about 2-1/2-inch to 3-inch square billetsv cut in half, and resoaked for about one hour at about 2100F. - ~
One sample was then hot-rolled to one-inch plate and the other ~ ;
sample hot-rolled to 5/8-inoh square bar stock. To test the cold workability of the alloy, the 5/8-inch square bar s~ock -was tested by forming wire usin~ two different proced~res:
1) Anneal for one hour at 2100F. and machin~d to 9/16-inch diameter draw bar. The bar was drawn to 0.062-inch diameter :
wire with intermediate anneals at 2100F.; 2) Anneal for about~one hour at 2100F., cold roll 8 passes in a rollin~
mill, anneal for about 1/2 hour at 2100F., cold roll,an ,~ additional 8 passes and anneal for about 1/2 hour at 2100~F.
Cold roll 3 passes and swage to .14-inch diameter wire. The wire was then centerless ground to 1/8-inch diameter.

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Weld screening tests were performed by employing ~
autogenous Bead-on-Plate test on the hot-rolled 1-inch plate using an automatic gas tungs-ten-arc at about 250 amperes, 11 volts and 16-inch/minute (ipm) travel speed. The weld deposi~ and attendant heat-affected zone were examined for cracking visually and at ten magnifications (lOX) with a --binocular microscope. The results of the weldability and ;~
workability tests are shown hereinbelow in Table II.
TABLE I

Alloy: C : Mn : Si : Cr : Mo : Al : Fë : B
No. : % ~ ~ %

1 :0.007 : 0.26 : 0.32 : 21.8 : 6.0 : 0.03 : 19.4 : 0.13 2 :0.007 : 0.29 : 0.30 : 22.6 : 6.0 : 0.021: 19.1 : 0.29 :
` 3 :0.005 : 0.25 : 0.27 : 22.6 : 6.0 : 0.036: 19.2 : 0.40 , : : : : : : : : .
4 :0.035 : 0.19 : 0.33 : 21.2 : 5.8 : 0.1~ : 20.1 : 0.15 ~
: : : : : : : . -- ~ , :0.042 : 0.22 : 0.31 : 28.4 : 5.9 : 0.080. 11.4 ; 0.30 ~
. : : . . , ~
6 :0.032 : 0.17 : 0.30 : 21.8 : 6.2 : 0.035 38.0 ~ 0.13 : : : : : : : :
7 :0.031 : 0.17 : 0.30 : 22.3 : 6.3 : 0.028: 47.4 : 0.15 ~ 8 :0.036 : 0.30 : 0.35 : 21.2 : 6.1 : 0.13 ; 19.4 . 0.19 i~ 20 9 :0.033 : 4.25 : 0.32 : 21.2 : 6.0 : 0.044. 19.2 : 0.17 ,.: . , , :
:0.03~ : 0.30 : 0.42 : 21.5 : 6.0 : 0.016; 19.5 . 0.79 ` 11 :0.085 : 0.24 : 0.25': 21.2 : 6~1 : 0.10 . 18.4 ; 0.22 `~ 12 Ø032 o.?l . 0.30 . 21.4 . 4.0 . 0.045 19.8 . O.~S

13 Ø11 . 0.22 . 0.26 . 21.5 5.9 . 0.036~ 20.0 ~ 0.18 14 :0~035 : 0.018: 0~33 : 21.5 : 5.9 : 0~032: 19.2 : 0.15 ~
;`~ 15 :0.031 : 1.55 : 0.32 : 21.9 : 5.9 : 0.031- 19.1 . 0.15 ~ ~
~ : : : : : : :.: :- :
~ 16 :0.033 : 0.21 : 0.05 : 21.7 : 6.0 : 0.020: 19.2 : Q;12 ,, : : :
17 :0.030 : 0.20 : 0.49 : 21.6 : 5.9 : 0~013: 19.3 : 0.13 18 :0.035 : 0.25 : 0.89 : 21.4 : 6.0 : 0.030: 19.2 : 0.14 ~ -j : : : . .
~ 30 19 :0.032 : 0.21 : 0.30 : 21.4 : 4.0 : 0.045. 19.8 . 0.25 .~ , - : : : : : : ' `
:0O033 : 0.18 : 0.32 : 21.9 : 8.8 : 0.015; 19.1 ; 0.14 , Cont'd.

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Alloy: C : Mn Si : Cr : Mo : Al : Fe : B
No. : ~ : % % %
21 : 0.033: 0.~1 : 0.24 : 22.3 : 4.2 : 0.036: 40.8 : 0.28 22 : 0.005: 0.25 : 0.27 : 22.6 6.0 : 0.036: 19.2 : 0.40 A : 0.51 : 0.12 : 0.29 : 22.2 : 4.2 : 0.019: 22.1 : 0.23 :
B : 0.011: 4.3 : 2.9 : 20.7 : 6.3 : 0.05 : 19.6 : 0.30 , : : : : : : :
C : 0.014: 0.27 : 3.1 : 23.9 : 6.1 : 0.09 : 19.3 : 0.30 - : : : : : : : -D : 0.004. 0.26 : 0.30 : 21.8 : 6.0 : 0.04 : 18.8 . nil io E . 0.031~ 0.34 0.30 21.5 . 5.9 0.017. 19.5 . 0.037 . : : : : ; : : -F : 0.037: 0.22 : 0.27 : 19.6 : 5.5 : 0.022: 1.3 . 0.26 G : 0.029: 0.23 : 0.30 : 22.1 : 5.6 : 0.063: 3.6 ~ 0.16 :
H : 0.30 : 0.21 : 0.27 : 21.4 : 5.95: 0.061: 20.0 . 0.21 I : 0.031: 0.25 : 0.27 : 17.2 : 5.84: 0.048: 21.4 : 0.25 :, : : :
J* : 0.032: 0.28 : 0.29 : 21.5 : 6.0 : 0.11 : 19.2 : 0.006 K : 0.029: 0.19 : 0.31 : 21.8 : 8.7 : 0.032: 13.3 : 0.001 L : 0.025: 0.28 : 0.34 : 21.2 : 6.0 : 0.013: 19.3 : 0.092 NOTE: Balance Ni * = 0.17 Ti and 0.018 Mg TABLE II

Alloy: ~lot : Cold :Bead-On-Plate ~
-` No. : Workability : Worka~ility : Test ~-1 : OK : OK : OK
2 : QK : OK : OK -

3 . OK . OK .~ OK
- :

4 . OK : OK : OK
.; i i . :

5 . OK :OK, Difficult to work. OK~

6 .OR tsmokedll OK . OK

7 .OK ~smoked) . OK . OK

- 8 :OK,Difficult to work. N.T. . OK

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TAsLE II cont'd.

9 OK Minor Cracking OK

10 .Edge Cracking ;Broke Up OK

11 . OK OK,Difficult to work .

12 OK . OK . OK

13 .Slight Edge Cracking.Broke Up

14 :Slight Edge Cracking: OK ; OK
.

15 OK ~ OK ; OK

16 Slight Edge Cracking. OK . OK

17 :Slight Edge Cracking: `OK OK

18 OK . OK . OK
.

19 : OK OK . OK

20 :Some E:dge Cracking . OK OK

21 . OK OK . OK
- ~22 : OR : OK . OK
A .Broke Up N . T . N . T . .
B : N.T. : N.T. :Severe Weld ,-~
C .Edge Cràcking .Broke Up . Crack ng ` ~`
D .Broke Up ~ N.T. . N.T.
E :Slight Edge Cracking: OK Severe Weld : ~-;
F OK .Some End Cracking ~Severe Crgcki '~ `
i G* : OK :Minor Cracking . OK
H :Broke Up ; N.T. N.T.
.
Slight Edge Cracking~ OX . OK
J* .Some Edge Cracking . OK OK `
-~ K Broke Up . N.T. ~N.T.
` L* : OK : OK ; OK
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; 30 * = These alloys failed the welding tests in 1" plate , ~ as shown hereinbelow in Example II.
: N~To ~ Not Tested i~.

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As can be seen from the results shown hereinabove in Table II, all the alloys of the invention passed the Bead-on-! Plate weldability test and most ~f the alloy~ of the invention exhibited excellent hot workability and cold workability properties, e.g., Alloys Nos. 2,3,4,12,19 and 22 are alloys within the preferred compositional range and show excellent hot workability and cold workability. The other alloys of the invention are examples of compo~itional ranges outside the preferred ranges and evldence the effect of producing an alloy having a composition outside the preferred range-s.
The results concerning the alloys outside the invention clearly demonstrate however, that the composition must be maintained within the broad ranges in order to produce an alloy having the desired characteristics. Regarding work-ability, for example, Alloy Nos. A and H show the di~sastrous effect caused by a high carbon content, to wit, greater than 0.30%. The other alloys similarly show the detrimental effects of silicon, chromium, iron and boron.
As a further demonstration of the excellen~t cold working characteristics of the preferred alloy, the hot rolled ~-1/2 inch plate of Alloy No. 4 was surfaced and cold rolled to 0.130-inch thick without intermediate annealing; this r~pre~ents a 74% reduction. This sheet was then annealed for about 1/2 ~' hour at 2100F. and cold rolled to .050-inch thick }heet, a ` reduction of 62~. The resulting sheet was of excellent quality, there being no evidence of tearing or edge cracking. Discs of ~'~ 60, 64 and 70 millim~ter~ (mm) diameter were cut from this ~heet and subjected to the Swift Cup Te~t. No defects were found in the8e specimens and they exhibited excellent drawing characteristics.
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To demonstrate ~he ability of alloys of this invention to be used as filler metals, ~ number of the alloys shown herein-above in Table I were employed under conditions imposing severe restraint to weld l/2-inch and l-inch thick plates. The 1/2-inch plate had a 60 V-bevel, a 3/32-inch root face and a 1/8-inch root opening. The l-inch plate had a U-groove preparation (15 bevel, 1/4-inch radius, 3/32-inch root face and 1/8-inch root opening).
Three methods o~ welding were employed, to wit, Manual Gas Tungsten-Arc tGTA) at 16 volts, 200 amperes, at a speed of approximately 3 ipm; Automatic ~as Metal-Arc (G~) at 33 volts, 300 amperes and 10 ipm; and manual covered electrode ~CE) at 24 volts, 85 amperes and approximately 3 ipm. As described hereinabove in Example I, the 1/8-inch wire was usPd for the GTA welds and the .062-inch wire was used for the GM~ welds.
The base plate compositions are given hereinbelow in Table III
and represent typical materials contemplated to be welded using alloys of this invention. Table IV shows the details of the tests on the welded joints and Table V shows the results of standard stress rupture-life tests performed on the transverse weId slices. The welding tests shown hereinbelow in Table IV
were performed by cutting ~he welded joints into transverse slices, polishing, etching with Lepito's reagent and examining for cracki~g at lOX with a binocular microscope. About 6 or 7 .; , slices (12 or 14 transverse faces) per welded joint were examined.
`~ The Bend-Tests were performed by bending a 3/8-inch transverse weld slice about a 1-1/2-inch diameter pin. These were reexamined microscopically at 10X for defects.
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-11- . ~' .tS~35 TABLE III
.
Alloy: C : Mn . Sl Cr : Mo : Al : Fe : B : Ni No. : % ~ % : ~ : % % ~ %
. .. .. .. . _ _ . . .. . _ _ BPl : 0.017: 0.27: 3.2 : 24.1 : 6.0:0.11 : 19.3 :0.32:(46.68) :
BP2 : 0.01 : 0.26: 3.18: 22.6 : 6.0:0.11 : 18.9 :0.31:(~8.63) :
BP3 : 0.05 : 0.21: 0.26: 15.7 :N.A.:0.10 : 7.1 :N.A.:(76.58) BP4 : 0.05 : 0.88: 0.39: 20.92:N.A.:N.A. : 46.9 :N.A.:(30.86) BP5 : 0.011: 0.48: 2.9 : 21.4 : 6.8:N.A. : 19.0 :0.~1~(49.1) :
BP6 : 0.01 : 0.25: 3.15: 21.8 : 6.1:0.12 : 18.9 :0.32:(49.35) BP7 : 0.90 : 2.28: 2.76: 20.0 :N.A.:0.01 :(33.42):0.13: 40.5 :
BP8 : 0.016: 0.20: 3.17: 22.0 : 6.1:0.013: 18.2 :0.34:(49.96) BP9 : 0.020: 0.22: 3.20: 22.0 : 6.1:0.01 : 18.1 :0.33:(50.02) : . : : : : : : : : : ~
BP10 : 0.44 : 0.96: 1.84: 26.0 :N.A.:0.047:(50.31):N.A.: 20.4 BPll : 0.03 : 0.86: 0.33: 20.9 :N.A.:0.36 :(45.72):N.A.: 31.8 :: : : : : : : : : : ~
;, BP12 : : : : : : : ~
-,,, : : : : :. : : : :
BPl3~: 0.01 : 0.5 : 0.2 : 21.0 : : 9 : 19 :N.A.: Bal.

'(j = Calculated b~ dif~erence N.A. = Not Added ~ ~ * = Nominal composition - also contains 1.5 Cr and 0.5W ~;
;' 20 TABLE IV

Weld Filler:Base Plate:Process:Plate : Cracks/Sec~ion No.:Alloy :Alloy No. : :Thick-:Transverse:Bend Test : No. : ~ : ness : Slices :(Bend! Angle) . .- --- _ - ... _. _ _ _ -- . , :
~ 1 : 1 :BP7 : GTA : 1/2 : 0 : N.T. ~ ~
, : : : : : ~ ~ -2 : 12 :BP8 : GTA : 1 : 0 : N.T. ;~
3 : 1 :BP2 : GMA : 1 : 0 : N.T.
,~, : : : : : : .
~' 4 : 2 .BP5 : CE : 1 : 0 : N.T.

¦ 5 : 1 :~P3/BP4 : GTA : 1/2 : 0 : N.T.
:~
6 : 3 :BP9/BP10 : GM~ : 1 : O : N.T.
: : : : : :
30 7 : 3 :BP9/~Pll : GMA : 1 : 0 : N.T.
:
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cont'd.
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TABLE_IV (cont'd.) Weld:Filler:Base Plate:Process:Plate _Cracks7Section No~:Alloy :Alloy No. : :Thick-:Transverse:Bend Test : No. : : : ness : Slices :(Bend Angle) . _ ... . . .. _ . ....... _ _ . . _ _ . ... .
8 : 3 :BP12 : GMA : 1/2 : O : ~.T.
9 :14 :14 : GTA : 1 : .11 :3(180) ~ ' :
15 .15 GTA . 1 0 6(180) 11 :9 : 9 : GTA : 1 : 0 :(6) (780j : . :
: 12 :16 :I~6 : GTA : 1 : 0 :(6) (82) . 10 13 :17 :17 : GTA ~ 1 : .11 : 8 (180) -:
14 :18 :18 : GTA : 1 : 0 :(6) (80) ~
: : : : : ~:, : 5: 5 : GMA : 1 : O :(6) (80) . 16 :19 :19 : GTA : 1 . 0 : 0 (180) :
-. 17 :20 :20 : GTA : 1 ; .22 : 6 (180) ~ ~ .
: : : : : : : . :
18 : 6 : 6 : GTA : 1 : 0 . 0 (180) 19 :7 : 7 : GTA : 1 : O :(6) (42) ~-,: : : : :::
. 20. : 21 :21 : GTA : 1 : O :(6) (66) : .
21 : 22 :BP6 : GMA : :L : O : N.T. ~: ~
. ~ :
. 22 : 4 : 10: GTA : :L : 0 :(6) (2~) -, 20 23 : 1 :BPl : GTA :1/2 : 0 : N.T. ~ :, 24 : 2 :~P5 : GTA :1/2 : : N.T! .~
: ` : : : :: : . .
l 25 : 3 :BP5 : GTA :1/2 : 0 : N.T.
, :
:26 : 3 : 2 :- GTA : 1 ; O : N.T. . : `
:: . . .
~ A I IGTA 1 1.6 N.T. . ~ :
: . ~. , :
`B : F : F : GMA : 1 : Severe ~ N.T.............. ~, :
: : : : iCracking : .
: : : : :2nd pass : ~
C : G : G : GTA : 1 : 5.1 :(6) (13) ^ ~: :

~ D : ~ : 71794 : GMA : 1 :Cracked : N.T. : :
.~ 30 : : : : :2nd pass E : J : J : GMA : 1 : Cracked :
. : : : . : :2nd pass : N.T.
:j F : L : L : GTA : 1 : 1.8 7 (180) ,, .. .. I ~
j N.T. = Not Tested ;l ; () = Bend Specimen broke in half :` .;.':
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TABL~ V

WeLd: Rupture Life at 1600F. (hours) Stress in Rsi No.:12,000 :10,000 :8,000 :7,000 : 6,000 1 : : : : : 308.2 2 : :37.7 :147.7 : : 788.5 :
3 : :13.6 :75.7 :218.7 : ~35.7 :
. 9 83.7 .222.8 703.9 10 : :142.2 :~61.6 : : : : :
: 11 : :126.9 :233.8 :
1012 : 154.4 :498.1 :1857.4 ~ : : : : :
13 : :82.0 :3~0.9 :515.1 :
14 : :51.4 :177.5 :1220.8 . 15 : :50.8 :406.4 :
:, 16 : : 116.2 : 660.0 : :
` .18 : :38.1: 86.0 : : 585.0 :
` 19 : :18.5: 47.6 : : 712.8 : ' ~ , 20 : :125.5 : 271.3 : : ~ ~
~ : : , .' 21 : - :29.6 :258.6 : : 12~2.6 - ~.~
: . : : ' , ~ -

22 : 107.7 :296.5 : :327.6 : :~

23 : : ~ :56.6 : : 692.5

24 : : 9.2 :46.7 :144.1 : 842.7 :, : : : : : :

25 : : 12.2.. - : 74.1 : 100.1 : ~
:

26 : : 65.2 : : : 3129.2 - . . -:
` . As can be seen from the results shown hereinabove in .
` Table IV, filler metals of the ~vention were used to prepare ~ :
Weld Nos. 1-26. All these welds were acceptable with either no cracks per section or a level of less than about .2 cracks .
:~ per section. Thesa results should be contrasted with the results shown for Weld Nos. A-F which were performed using 30 . filler metals outside the invention. All these welds showed :~ ~
. . - .
. :. . . .
:.`' ' . -:
~ - . :
.

- . . : . . ., :, .-.,.,. :- .:. ~ . . -~.~?5;~ 5 numerous cracks per section and in the case of Weld Nos. B, D
and E, they cracked so severely during the second pass that these joints could not be completed. Analysis of the welds prepared using alloys of the invention shows the tendency towards weld cracking when the limits for various elements are approached. For example, Weld Nos. 9 and 13 ~hich exhibited .11 cracks per section employed a filler wire containing .15%
and .13~ boron, respectively, ~which are near the lower limit of about 0.1~ for that element. Weld No. 17 contained .14%
boron and 8.8% molybdenum ~a high level for this element) and ~ `
exhibited .22 cracks per section.
The stress-rupture characteristics of the welded joints shown hereinabove in Table V indicate the excellent load- ~ ~ ~
bearing capacities of the alloys of this invention at elevated `;, temperatures.
EXAMPLE III `
To demonstrate the oxidation-resistance of the alloys of the invention, the welds described hereinabove in Example II
were tested by exposing specimens in an air-5~ water atmosphere at 1000C., using a 24 hour cycle for a 500 hour test duration.
The air-water mixture was flowing at 250 cubic centimeters per ``-~
minute (cc/min) over th~ specimens, which were machined from :, .
-~ the welded joints. The specimens were machined with the weld deposit comprising approximately 50% of the total specimen.
The weight changesof the specimens were tested in both the ~, un-descaled and descal~d conditions. The specimens were removed i~ from the testing apparatus and allowed to air cool to room temperature; the weight change was measured (un-descaled condition), the specimens were lightly descaled to remove the `~ 30 oxide formed and the descaled weight change of the specimens : ~ .
:
..;
: . ;
,'' ' ' was measured. Descallng of all test specimens was done an S.S. White precision abrasive cleaning unit using 50 micron alumina propelled by dry C02. The 500 hour exposure weight change results shown hereinbelow in Table VI evidence the excellent oxidation-resistance of the preferred alloys of the invention, whereas welds prepared from filler wires not of the preferred composition have a decreased oxidation resistance.
For example, Weld Nos. 18 and 19 prepared from filler wires - containing high percentages o~ iron showed a decreased oxida-- 10 tion resistance. As noted hereinabove however, alloys outside the preferred compositional range while having a decreased oxidation resistance, nevertheless, may be suitably employed for many industrial applications not requiring the excellent oxida~on resistance characteristic of preferred alloys of ~
; this invention. ~ -TABLE VI

Weld : Undescaled : Descaled No. :Weight Change (mg/cm2) :Welght Change (mg/cm2) 9 : --,59 : -10.58 , . `: .
.-1.4~ -11.88 ; 11 .-7.02 -12.7 12 . .24 . - 8.33 13 -1.55 -11.75 ' -~

~, 14 ~-1.12 -13.85 ;~ , :3.66 . 1~.46 16 :-1.08 : -11.17 18 -52.2 ~ . -63.4 ; 19 Test discontinued after 72 hours due to extreme attack 21 ;~ .40 ; -10.67 -'i : .
j 30 22 .- 1.34 . -12.97 24 :- 3.33 . -11.65 ~ -:- 2.93 ; -10.65 : ~ . .

.: ' ' ' .

.

tj~35 EXAMPLE IV ~, ,- To demonstrate the tensile properties of alloys of the invention and of the welded joints, room and elevated temperature tensile tests were performed; the results of which are shown hereinbelow in Table VII. Alloy No. 1 was prepared as shown hereinabove in Example I, with the 5/8-inch square bar skock being further heat treated by annealing for one hour at 1950F., followed by air cooling,. Weld No. 3 was tested in the as-welded condition. - ~,' ;

"

Alloy:Weld:Temp.,:0.2~ Y.S.,: U.T.S.,:Elong.: R.A.,:Fracture , No. : No.: F. : (ksi) : ~ksi) :in 1"%: % :Location : 70 : 46.5: 115.4; 21.0 ~ 55.8 ' - '' ,, : : : ;., .: .
~, : : 1400 : 30.4 55.0 34.0 34.0 ! ~
~ : : 1600 : 24.6 : 30.0 : 80.5 : 70.0 : ,', ~ , :- .
: : 1800 : 12.7 : 15.8 : 79.0 . 63.0 ~ ,'`'~-:~ - . 3 70 . 56.0 . 78.6 . 5.0 . 12.2 . Base , '', ~ : : 1400 : 33.6 : 50.2 : 10.5 : 16.0 : Base ,i : : 1600 : 2Ø6 : 29.3 : 17.5 ; 44.8 ; Base ' `

` , EXAMPLE V ,-:~

To demonstrate the corrosion-resistance of alloys of , the invention, two standard corrosion tests were performed;

,'J 1) crevice corrosion test and 2) Huey test. The crevice corrosion test was performed using a 10% ferric chloride ~ "~

;l solution at room temperature. The l-inch wrought plate pre~

, pared in accordance with Example I was machined to form a teqt ,~

~¦ specimen l-inch by 2-inch by 3/16-inch ~1" x 2" x 3/16"). A

~I rubber band 1/4-inch wide ~as placed along the length of the specimen and the specimen then suspended in the ferric chloride ''~

solution ~or a period of 72 hours at 70F. After this period, :::

.,: - - - '`; -'- ~ ,,, , ., , . :.

~5~,13S

the samples were tested for their resistance to corrosion : by measuring the weight 108s in milligrams/square decimeter/
day (mdd). The Huey te~ were performed in accord~nce with the procedure~ outlined in recommended practice C of ASTM
A-262 by exposin~, to a boiling 653 ni~ric acid environment for 48 hour periods, a specimen machined from the wrought alloy prepared in Example I~ After each period the samples were tested for their resistance to corrosion by measuring : the weight loss and mdd and the xesults shown hereinbelow ; :.
.~ 10 in Table VIII show the weight loss at the end of 5 periods ~:
(total expo~ure 240 hours) and also indicates whether or not ~ .
the corxo~lon was accelerating (A) or maintaining constancy (C) over the 5 test periods. Similarly, the wei~ht lo~s for the samples exposed to the ferric chloride ~olution are also . ~ ~
::. shown in Table VIII and represent the weight 108s after the ~ :
:: :
one exposure period of 72 hours.
` j .~ ' ' ~' :~, . j. .

.. , ' ' .'' ', .,"
. : :. .
. ;~ . ' ' ~.- :
., ' .~ , ~ :
.` 1 . ' ' ~ , . . . - ~ .

:'`~ . ' : i "

:,`j . : ' `,;

., . ' '. ~
, -18- ~ ~

.:', :"'~ . :
' s TABLE VI I I
~ . . .
Al loy ~ -I Te s t ( 1 ) ~ (mdd ) Co~r s ion rate 4 : 586 :100. 5 A
:
6 : 51 :41. 8 : C
7 . 7 .40.3 . C ~ -9 1124 94 . 3 A : -,. : : : - : :-,: ' . 12 : 644 :36. 6 : C ~.
~ - - .
14 : 665 :47 . 3 : C .~ ;
1015 ~14 2 5 6 9 . 6 A ;~ . -1 6 :5 0 4 :3 9 . 2 ~ C
17 : 523 :74 . 9 A
~, . 1 18 : 506 :86 . 2 : A
,` 20 : 5 :84.2 ; C
. `~
G ~ 596 58.3 . C - ~ ~ -J 3 6 5 :6 1 .1 : A . . ~ ~
.1 -~:. `, . .
Although ~he preaent invention has been de~cribed in conjunc~ion with preferred embodiments, it is to be under~
stood that modification~ and variations may be re~orted to ~-;~ ~0 withbut departinq from the spirit and ~cope of the invention, .as those skilled in the art will readily understand. Such ~;
:~ modifications and variation~ are con~idered to be within the 3 purview and ~cope of the invention and appended claims~

.`: -..

t.

-19- ~ ~
.
~. .

Claims (8)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A workable and weldable alloy consisting essentially of (by weight) up to about 0.2% carbon, up to about 4.5% manganese, up to about 1.5% silicon, from about 18% to about 30% chromium, from about 5% to about 50% iron, from about 0.1% to about 1%
boron, from about 3% to about 9% molybdenum, and the balance essentially nickel.

2. An alloy in accordance with claim 1 containing up to about 0.1% carbon, up to about 2% manganese, up to about 1%
silicon, from about 19% to about 24% chromium, from about 15%
to about 25% iron, from about 0.12% to about 0.4% boron, from about 4% to about 8% molybdenum, and the balance, in an amount of at least about 30%, essentially nickel.

3, An alloy in accordance with claim 2 containing from about 0.003% to about 0.06% carbon, up to about 1% manganese, up to about 0.4% silicon, from about 20% to about 24% chromium, from about 17% to about 23% iron, from about 0.15% to about 0.4% boron, from about 5% to about 7% molybdenum, and the balance, in an amount of at least about 30%, essentially nickel.

4. An alloy in accordance with claim 1, wherein the iron is in an amount from about 40% to about 50%.

5. An alloy in accordance with claim 1, wherein the molyb-denum is in an amount from about 8% to about 9%.

6. As a new article of manufacture, a wrought filler metal having a composition as set forth in claim 1.

7. As a new article of manufacture, a wrought filler metal having a composition as set forth in claim 2.

8. As a new article of manufacture, a wrought filler metal having a composition as set forth in claim 3.