FiS- 2— M ultiple fla m e heads fo r pressure w eld in g o f railroad rails. Flam es directed do w n w a rd on to p surface o f rail are o f uniform size, w hereas fla m es directed against side, w e b and base o f rail are proportioned to (hickness of
section against w hich th e y im p in g e
This
newoxyacetylene method makes welds by
coalescenceof
g ra in s acrossweld interface at subfusion temperatures under controlled tem perature and m oderate pressure. First described by the author before a meeting of the American W elding Society, its efficacy as a joining medium for overland pipelines, railroad rails, oil-w ell tool joints, d rill and spring steel, stainless, and even low-carbon plate, is am ply demonstrated by results of tests and
case histories reported in this article
By A. R. LYTLE
nion C arbid e and C arb o n Research Laboratories Inc.
N ia g a r a Falls, N. Y.
'day 2 1, 1945
115
TEN SILE PRO PERTIES O F PRESSURE W ELD S IN TYPICAL ALLOYS AND APPLICATIONS (REIN FO R C EM EN T REM OV ED FRO M W E L D IN ALL CASES)
TABLE X
Approx. Lbs. P er Sq. In. P er Cent Per Cent Bend
Dimensions H eat Yield Tensile Elong. Reduction Elong.
M aterial of W eld T reatm ent Point Strength in 2 in. of Area Vz in. Tensile F ra ctu r
W rought Iron L i n k s ... 94 in. diam . A .W .° T otal load, 4 3 ,0 0 0 1 Shear Break Overland Pipe ... 6 in. diam.
62,300
1 X ft-in . wall A.W . 35,000 F lat Base Metal
0.10% C D eep-D raw n 15 in. diam.
Steel S h e l l s ... X Jé-in. w all A.W. 2 7,200 48,300 23.8 F lat Base M etal Reinforcing Bars
SAE 1030 ... 2 in. square A.W. 3 6,000 72,400 Base Metal
SAE 1045 ... 1V4 in. diam . A.W. 65,000 104,000 . . . . Base M etal
114 in. diam. T .N .0 64,000 98,000 Base M etal
0.S0 C Rail Steel ... 1121b. rail T.N. 61,450 130,250 14.8 2 0 T Base M etal
0.00 C Steel Spring Leaves . . . . 3 in. X % in. Orig. 126,000 186,600 3.0 4.7 Base Metal
P .W . & H .T. 125,000 190,800 11.3 19.1 Base Metal
Tool Joints ... 5 in. diam . x
%-in. wall T.N. 69,400 105,900 33% D rill Pipe
Stainless Steel to Nickel Alloy. . . . Bars A.W. 37,800 95,700 26.3 35.9 20% Stainless Steel
N E 8630 ... 14-in. p late A.W. 70,900 103,600 Base M etal
Shear Blades 12% C r Steel to
Low-Carbon Steel . ... 14-in. X 6 in. A.W. 32,200 58,900 In L ow -C arbon S
18 Cr-8 N i C b ... 114-in. bars A.W. 31,700 84,700 39.8 53.8 W eld SAE 4340 ... 14-in. plate H .T .° 186,500 200,100 8% Base M etal
°A .W . = . As-welded— reinforcem ent rem oved.
T.N . = T orch-norm alized.
H .T. = Furnace heat-treated.
JH and-w elded links average 33,000 lbs. to tal load w ith shear fracture.
been designed an d are in c u rre n t use.
H ow ever, in m any operations p lain end p ressu re is perm issible. B oth types, of course, should be su p p lem en ted b y p ro p e r guid an ce to p re v e n t m isalign
m ent. E xperience has show n th a t h y draulic o r fluid p ressu re e q u ip m e n t is alm ost id eal fo r this pu rp o se, as it is read ily v ariable, is su b ject to m echanical as w ell as m an u al control, a n d w ill m ain
tain p ressu re regardless o f expansion o r contraction of th e specim ens b ein g w elded.
C apacity o f th e p ressu re eq u ip m en t, o f course, w ould d e p e n d upon th e size o f th e w ork. M ost p ressu re w elding now b ein g done is carried o u t a t pressures of from 2500 to 4000 psi of a b u ttin g sur
face. W elds can b e m ad e w ith the p ressu re as low as 1500 psi, b u t u p settin g a t this p ressu re is ra th e r slow. F o r w eld in g steels th a t h a v e hig h stren g th a t hig h tem p eratu res, such as th e ch ro m ium an d chrom ium -nickel steels, th e u n it pressures m ay b e as hig h as 4500 psi. T his w ould b e expected from th e physical p ro p erties of th ese alloys.
B low pipe E q u ip m en t: As indicated, uniform a n d controlled local h eatin g is one o f th e essential req u irem en ts for successful p ressu re w elding. I t is nec
essary th a t th e h e a t supply b e p ro p o r
tio n ed to th e dim ensions o f th e speci
m en being w e ld e d so th a t th e rate of tem p e ra tu re rise is uniform th ro u g h o u t th e section, as it is necessary to b rin g th e in terio r of th e specim en to th e w eld ing te m p e ra tu re w ith o u t overh eatin g th e external surface. F o r p ractical purposes,
TABLE II
BESULTS O F KKOUSE FA TIG U E TESTS— 10,000,000 CYCLES O F STRESS
Approx. Per «
M aterial Dimensions H eat Endurance E.;
of W eld T reatm ent Lim it, P SI T.
L ow -C arbon P l a t e ... % in. x 6 in. A.W . 32,000 Ą SAE 1045 ... 1% in. diam . T.N . 48,000 Ą
W .Q . & D. 58,000 4
R ail S t e e l ... 112-lb. rails T.N . 56,500 4
Tool Joints Low- 5 in. diam . x
Alloy S t e e l ... % -in. w all T.N . 50,500 4 Stainless Alloy to
N ickel A l l o y ... Bars A .W . 50,500 e
N E 8630 ... %-in. p late A .W . 56,000 c
H .T . 72,000 4
SAE 43 4 0 ... %-in. p late H .T . 55,000 c
TABLE H I
RESULTS O F N O T C H E D CHARPY IM PACT TESTS Approx.
M aterial Dimensions H eat Char
a t W eld T reatm ent Val
0.10% C a r b o n ... Original 21.1
A .W . 21.1
SAE 1045 ... A.W. 4 .’
As received 17.«
T.N. 28.«
W .Q . & D. 31.(
Low-Alloy Tool Joints ... 5 in. O.D . x
% in. w all T.N. 24.(
R ail Steel ... 112 lb. rail O riginal 3.1
T.N. 3,(
Spring Steel ... O riginal 4.]
P.W . & H .T. 4.S
•S pecial notched specimens.
req u irem en ts of uniform an d controlled h eatin g are b e st secu red b y m u ltip le sm all oxyacetylene flames such as are w idely u sed fo r flam e-hardening o p era
tions. T h is ty p e of h e atin g p erm its a w ide la titu d e in th e b alancing o f local h e a t in p u t w ith th e h e a t req u irem en ts
Fig. 3— Pressure w e ld in 1 /2 - in ch th ic k boiler plate. A p p ea r
ance is typ ica l o f g o cd quality pressure w e ld , w ith u n ifo rm grain structure through w e ld zone and sm ooth contour o f u p set m etal
116 / T E I
B Y REVERE
Available in coils or straight lengths, depending on size and com position. For full details, prices and deliveries, consult your Revere distributor or us. The Revere Technical Advisory Service w ill gladly work w ith you in selecting the rod best fitted for your needs. For tnis assistance, which is given without obligation, just write the Revere Executive Offices.
COPPER AND BRASS INCORPORATED Founded by P a u l R et ere in 1801 Executive Offices: 230 P ark Ave.. N . Y. 17, N . Y.
May 21, 1945
F ig. 4 — T im e re
quired fo r pressure w eld in g in respect to thickness. . R elation
ship is practically lin- and holds getter- m o st condi- and
a t th a t p a rtic u la r point. In practically every application, h eatin g flames are di
rected against one side only, th e ex
cep tio n b ein g som e cases of very heavy- w alled tu b in g fo r w hich econom y has favored app licatio n o f h e a t to b o th sides.
F ig . 2 show s a com bination of m ulti- p le -tip blow pipes th a t has b e e n devel
o p ed fo r p ressu re w elding of stan d ard railro a d rail. T h is is an excellent ex
am ple of th e ad ap ta b ility of such nm lti- p le -tip blow pipes to sections of vari
ous thicknesses a n d irreg u la r contour.
T h e h e a d o f a rail is a b o u t 2% inches w ide an d 1% inches d eep , th e w eb ab o u t
% -inch thick, a n d th e b ase tapers from a m axim um of 1 inch to % -inch in th ick ness. H ow ever, b y th e p ro p e r choice, size a n d position o f in sert tip s directed to w a rd th e various p arts of the rail, the ra te of h e a t in p u t h as b e e n pro p o rtio n ed so th a t all points of th e rail section reach th e w elding tem p e ra tu re a t p ra c tically th e sam e tim e a n d a t no point is th e re any u n d e r or overheating. In cases of uniform sections, such as pipe or b a r stock, th e w elding h e a d w o u ld c o n tain a series of tips w ith the sam e d rill size or w ould h av e a series of ori
fices d rilled in th e face of a ring or o th e r suitably sh ap ed h e atin g head.
In m o st instances it has b een fo u n d advisable to k eep th e b lo w p ip e in m o
tion in respect to th e m etal. In some cases o f cylindrical objects such as tubes, th e m aterial m ay b e caused to ro tate
w ith th e b lo w p ip e stationary, o r th e w elding h e a d m ay be given a slight cir
cu m feren tial oscillation. By m oving the h e a d b ack a n d fo rth across th e in te r
face, it is possible to h e a t th e desired w id th of zone w ith a b lo w p ip e of sm all
er dim ensions th an w o u ld b e necessary if th e en tire w id th of h e a te d zone w ere co v ered w ith stationary w elding flames. M oving th e blow pipes also p e r
m its th e use of la rg e r h e atin g flames w ith co n seq u en t econom y in w elding cost, d u e to red u ctio n in tim e req u ired fo r w eld in g a n d re d u ced loss o f h e a t by conduction. O ne instance in p a rtic u la r in w hich m ovem ent of th e flames is especially advantageous is in th e w eld ing of rail steel. T his h ig h -carb o n m a terial is very susceptible to b u rn in g , and th e area im m ediately u n d e r a b u rn e d spot w o u ld b e u n su ite d fo r u se in serv
ice. In this p a rtic u la r o p eratio n th e blow pipes are m oved to an d fro just en o u g h to p re v e n t th e form ation of a
spot o r zone of m elted m etal u n d e r th e h eatin g flames.
T ypes of Joints: T h e pressure-w eld-ing m eth o d is ideally a d a p te d to b u tt w eld in g in w hich th e opposing faces are p ractically th e sam e in size an d shape.
In pressure w eld in g m em bers of differ
e n t thicknesses, recourse u su ally is h ad to ta p e rin g tire la rg e r section to the sam e dim ension as th e sm aller to pro
vide eq u a l thickness a t th e joint. In th e p re s e n t state of this art, th e m ost im p o rta n t p o in t to consider in reg ard to th e shape b ein g w eld ed is w h e th e r it can b e h e a te d a d e q u a te ly b y a series of oxyacetylene flam es w ith o u t interfering w ith th e app licatio n of pressure.
C ontrol: T h e m e th o d u sed to con
tro l th e q u ality of th e w e ld o btained b y this process is obviously of g reat in terest, fo r u p o n p ro p e r control depend th e consistency an d q u ality of th e w elds p ro d u ced . T o u n d e rsta n d th e control m ethods, it is necessary to u n d erstan d th e en tire w eld in g p ro ced u re. Two tech n iq u es w hich differ only m echanical
ly h av e b een evolved fo r this w elding.
In one th e p ro c e d u re is p ractically as follow s:
E n d s to b e w eld ed are m ach in ed to a fairly sm ooth, clean finish. E n d p re p aratio n d ep en d s prim arily on th e com
position of b ase m etals b e in g w elded.
F o r average low -carbon steels, th e p rin cipal req u irem en t is cleanliness, as very satisfactory w elds h av e b e e n m ad e on a p ro d u ctio n basis w ith a ra th e r pooily m ating joint, b u t fo r th e h ig h e r car
b on an d m ore p articu larly th e alloy steels, close m atin g as w ell as cleanliness
F ig. 5— Pressure w eld in g m achine for w eld in g rails. S p ecim en s are clam ped fro m side w ith en d w eld in g pressure applied thro u g h clam ps. W e ld in g pres
sure is a p p lied through a m anually operated p u m p . In other larger m odels b o th gripping and w eld in g pressure are a pplied b y a m o to rized p u m p . S ta n d
ard 112-pound R E rails are b ein g w e ld e d here
Pig. 6 C lam p a nd b lo w p ip e e q u ip m e n t develo p ed fo r pressure w eld in g 24-in ch overland pipe. M aster clam p grips p ip e through one set o f clam ps a n d applies pressure thro u g h another. B oth sets are controlled fr o m a tractor.
A nnular b lo w p ip e is m o u n te d on fra m e o f clam p and m a y b e reciprocated m anually during w eld in g
ADAPTATION STYLE T-l
ADAPT
ATION STYLE T-l ADAPTATION
STYLE T-4 OR T-7 ADAPTATION
STYLE T-l TURNING AND
FORMING
ADAPTATION STYLE T -13 or T -14 ADAPTATION
STYLE T-4 OR T-7 ADAPTATION
STYLE T-4 OR T-7
UNDERCUTTING FORMING
BORING GROOVING