Welding under subzero temperature conditions

Publisher’s version / Version de l'éditeur:

Technical Translation (National Research Council of Canada. Division of Information Services), 1949-05-06

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.

https://nrc-publications.canada.ca/eng/copyright

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la

première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à [email protected].

Questions? Contact the NRC Publications Archive team at

[email protected]. If you wish to email the authors directly, please see the first page of the publication for their contact information.

NRC Publications Archive

Archives des publications du CNRC

For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.

https://doi.org/10.4224/20331507

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

Welding under subzero temperature conditions

Taran, V. D.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

NRC Publications Record / Notice d'Archives des publications de CNRC:

https://nrc-publications.canada.ca/eng/view/object/?id=e9f0dd01-81c6-426a-8756-8e4f95aaa328 https://publications-cnrc.canada.ca/fra/voir/objet/?id=e9f0dd01-81c6-426a-8756-8e4f95aaa328

NATIONAL RESEARCH LABOHATORIES

Ottawa

,

Canada

TECHNICAL TRANSLATION N O . IS-3

D i v i s i o n of I n f o r m t i o n . S e r v i c e s

T i t l e : Welding u n d e r Subzero T e m p e r a t u r e C o n d i t i o n s .

By: V.D. T a r a n .

R e f e r e n c e : Automotive I n d u s t r y , No. 9, 1947, pp, 12-16.

Automotive I n d u s t r y , No. 9 , 1947

WELDING UNDER SUB-ZERO TEh1PERR TURE C O N D I TIONS b y

P r o f . V.D. T a r a n

T r a n s l a t e d b y E s t h e r Habkin,

The m a n u f a c t u r e o f welded a s s e m b l i e s u n d e r w i n t e r c o n d i t i o n s a t low t e m p e r a t u r e i s o f t e n accompanied by a

d e s t r u c t i o n of t h e w e l d i n g m e t a l o r t h e seam. The breakdown of t h e m e t a l o c c u r s e i t h e r d u r i n g t h e time of w e l d i n g o r a t t h e f i n i s h o f a s e c t i o n o r o f t h e t o t a l c o n s t r u c t i o n . I t i s n a t u r a l t h e n i n o r d e r t o o b t a i n a p r o d u c t # o f a good quality, f o r t h e b u i l d i n g a n d i n s p e c t i o n o r g a n - i z a t i o n s t o i n t r o d u c e i n t o t h e t e c h n i c a l i n s t r u c t i o n s a l i m i t i n g low t e m p e r a t u r e , below which w e l d i n g s h o u l d n o t be c a r r i e d o u t .

Because o f i n s u f f ' i c i e n t s t u d y o f t h e phenomena,which c o n d i t i o n t h e a p p e a r a n c e o f c r a c k s a n d more s e r i o u s breakdowns i n t h e m e t a l , v e r y d i v e r s i f i e d f i g u r e s f o r t h i s l i m i t i n g

t e m p e r a t u r e e x i s t . For example one e n c o u n t e r s i n t h e

r e g u l a t i o n s of t h e B o i l e r I n s p e c t i o n v a l u e s o f O ° C e and - l O ° C e

a s t h e l i m i t i n g low t e m p e r a t u r e f o r w e l d i n g o f v e s s e l s c a r r i e d o u t u n d e r p r e s s u r e o i n t h e t e c h n i c a l i n s t r u c t i o n s o f t h e main

A

s t o r a g e o f benzene, t h e t e m p e r a t u r e i s -15OC. I n t h e new

t e c h n i c a l i n s t r u c t i o n s f o r t h e c o n s t r u c t i o n o f t h e main Evloscow g a s l i n e s t h e l i m i t i n g t e m p e r a t u r e was e s t a b l i s h e d a s - 1 8 O C . During w a r t i m e t h e temporary r e g u l a t i o n s o f t h e Department o f B u i l d i n g f o r t h e c o n s t r u c t i o n of s t e e l r e s e r v o i r s f o r t h e s t o r a g e of p e t r o l e u m p r o d u c t s a l l o w e d w e l d i n g s t o b e c a r r i e d o u t d u r i n g w i n t e r p e r i o d s a/s",{-zero t e m p e r a t u r e . The

examples i l l u s t r a t i n g t h e d i f f e r e n c e s i n t h e s e f i g u r e s c o u l d b e m u l t i p l i e d .

Due t o t h e l a r g e r e g i o n s of t h e S o v i e t Union, where c o n t i n u o u s low t e m p e r a t u r e s e x i s t f o r l o n g p e r i o d s , t h i s

problem becomes of g r e a t i m p o r t a n c e . Some T y p i c a l Cases o f Breakdowns

There a r e many c a s e s of breakdowns i n m e t a l l i c c o n s t r u c t i o n s due t o t h e f o r m a t i o n of c r a c k s w h i l e w e l d i n g u n d e r w i n t e r c o n d i t i o n s , U n f o r t u n a t e l y s u c h c a s e s a r e n o t a l w a y s c a r e f u l l y a n a l y z e d b y t e c h n i c i a n s i n o r d e r t o a c c u m u l a t e f a c t u a l d a t a on t h e c o n d i t i o n s o f t h e breakdowns, which s t r o n g l y h i n d e r s t h e p r e s e n t a t i o n of t h e problem a n d t h e removal of t h e c a u s e s . We w i l l d e s c r i b e s e v e r a l t y p i c a l c a s e s : 1. I n one o f t h e Moscow e s t a b l i s h m e n t s d o u b l e - 3 welded beams o f s o l i d c r o s s s e c t i o n and a h e i g h t o f 8 0 0 mm.

were b e i n g c o n s t r u c t e d . A q u a n t i t y of 12 beams were c o n s t r u c t e d i n t h e p l a n t a n d s t o r e d i n t h e p l a n t y a r d , Then t h e s p a c e

o c c u p i e d b y t h e beams was needed f o r something e l s e . I n t h e a b s e n c e o f a c r a n e t h e beams were moved b y hand w i t h c r o w b a r s a d i s t a n c e o f 8-10

M.

The m o t i o n was c a r r i e d o u t i n a

d i r e c t i o n p e r p e n d i c u l a r t o t h e a x i s of t h e beams, During t h e movement t h e beams were t i l t e d . T h i s o p e r a t i o n was c a r r i e d

o u t a t a t e m p e r a t u r e o f -30°C.

A f t e r the beams were moved t o t h e new p l a c e i t was f o u n d t h a t c r a c k s a p p e a r e d i n t h e welded seams. I n t h e m a j o r i t y of c a s e s t h e c r a c k s e x t e n d e d kbo t h e b a s e m e t a l and were f o u n d

t o be c o n t i n u o u s . The c r a c k s were o f v a r i o u s l e n g t h s f r o m s e v e r a l c e n t i m e t e r s t o t h r e e m e t e r s . The beams were welded w i t h e l e c t r o d e s h a v i n g a c h a l k y c o a t i n g .

2 , On a s h i p b u i l d i n g y a r d l o a d i n g masts were b e i n g p r e p a r e d from p i p e s , The m a s t s c o n s i s t e d o f i n d i v i d u a l p i p e s

which were c o n n e c t e d b y welded seams, t h e j o i n t s were s t r e n g t h e n e d w i t h r i g h t a n g l e d l i n i n g s ,

D u r i n g t h e w e l d i n g i n t h e p l a n t t h e work p r o c e e d e d w i t h o u t a n y d i f f i c u l t i e s , b u t d u r i n g t h e w e l d i n g on a n open p l a t f o r m a t a t e m p e r a t u r e o f -15OC, c a s e s o f c r a c k e d seams were o b s e r v e d , The c r a c k s were formed d u r i n g t h e p r o c e s s o f

t h e w e l d i n g o r s e v e r a l h o u r s l a t e r , I n t h r e e c a s e s c r a c k s Ln t h e b a s i c m e t a l , some d i s t a n c e f r o m t h e seam, were f o u n d , The c r a c k s formed a n a r c a r o u n d t h e l i n i n g s b u t d i d n o t r e a c h t h e seam which s e c u r e s t h e l i n i n g s t o t h e m a s t ( F i g , l ) , A l l t h e c r a c k s c o u l d b e v e r y c l e a r l y o b s e r v e d , f o r m i n g a maximum

gap of t h e o r d e r of 0,2--0.5 mrn, A t t e m p t s t o weld t h e c r a c k s a f t e r e d g e s have formed on them were n o t of t e n s u c c e s s f u l ,

s e c o n d a r y c r a c k i n g was o b s e r v e d ,

The f u r t h e r w e l d i n g of t h e m a s t s was c a r r i e d o u t i n t h e plar2t and no c r a c k s were o b s e r v e d , The p r o c e d u r e f o r t h e w e l d i n g i n t h e p l a n t a n d on t h e open p l a t f o r m was t h e

same, The w e l d i n g was c a r r i e d o u t w i t h t h i n l y c o a t e d e l e c t r o d e s , 3 . On t h e 1 7 t h o f December, 1 9 3 8 , i n one o f t h e

p e t r o l e u m works a v e r t i c a l c y l i n d r i c a l r e s e r v o i r o f 4685 M~ c a p a c i t y h a v i n g 3/4 of t h e volume f i l l e d w i t h c r u d e o i l , e x p l o d e d . The welded r e s e r v o i r was p u t i n t o u s e i n t h e summer of t h a t y e a r ,

The m e t e o r o l o g i c a l c o n d i t i o n s d u r i n g which t h e breakdown o c c u r r e d were a s f o l l o w s : cn t h o e v e o f t h e a c c i d e n t t h e a v e r a g e t e m p e r a t u r e was -24OC. t h e minimum f o r t h e 24 h o u r s was -27,5'C. t h e a v e r a g e wind v e l o c i t y was 6 , 3 M/sec, On t h e 1 7 t h o f

December t h e d a y o f t h e a c c i d e n t t h e a v e r a g e t e m p e r a t u r e was -23,6OC. The minimum f o r 2 4 h o u r s was -25,5OCO t h e a v e r a g e wind v e l o c i t y was 5 - 6 ~ / s e c ,

A s a r e s u l t o f t h e a c c i d e n t t h e r e s e r v o i r was t u r n e d o v e r . The c o v e r f e l l o f f on one s i d e a n d t h e c y l i n d r i c a l body on t h e o t h e r , The b r e a k o c c u r r e d a l o n g t h e l e n g t h o f t h e

c y l i n d r i c a l b o d y a n d a l o n g t h e t o t a l h e i g h t o f t h e r e s e r v o i r , p a r t i c u l a r l y a l o n g t h e seams and p r e d o m i n a n t l y i n t h e b a s i c m e t a l . I n t h e m a j o r i t y o f c a s e s t h e e d g e s o f t h e b r e a k were

v e r y uniform, which i n d i c a t e s t h a t i t was a b r i t t l e brqcak.

I n t h e lower p a r t of t h e r e s e r v o i r were founcq p a t c h e s c o v e r i n g s l n a l l c r a c k s whicki, a p p a r e n t l y , a p p e a r e d d u r i n g

c o n s t r u c t i o n . These c r a c k s were found t o b e i n rows a l o n g t h e seams which gave way d u r i n g t h e a c c i d e n t ,

T e s t s c a r r i e d o u t on t h e m e t a l a n d on t h e searns showed t h a t t h e welded seams were of a s a t i s f a c t o r y q u a l i t y and t h a t t h e b a s i c m e t a l was s t a n d a r d s t e e l o f mark Ct-3, R e s i l i e n c y t e s t s o f t h e b a s i c m e t a l a t v a r i o u s t e m p e r a t u r e s showed t h a t w i t h a l o w e r i n g i n t e m p e r a t u r e tho r e s i l i e n c y d e c r e a s e s , and t h a t t h e m e t a l becomes c o m p l e t e l y b r i t t l e a t a t e m p e r a t u r e below -30-40°C. 4. I. K u d r i a v t z e v ( 2 ) r e p o r t s a c a s e where b r i t t l e c r a c k s were found i n r o l l e d beams NO. 26 l y i n g i n a f a c t o r y y a r d a t a t e m p e r a t u r e o f -10--12°C, These beams were n o t s u b j e c t e d t o any a c t i o n .

5 , On one of t h e c o n s t r u c t i o n p l a t f o r m s t h e w e l d i n g of r e s e r v o i r s f o r t h e s t o r a g e of benzene was c a r r i e d o u t i n t h e w i n t e r t i m e . I n t h e n i g h t , a t a t e m p e r a t u r e o f a b o u t - 3 0 °

c r a c k s a p p e a r e d i n t h e bottoms of t h e u n f i n i s h e d r e s e r v o i r s , The c r a c k s were found i n t h e w e l d i n g seams and i n t h e b a s e m e t a l a l o n g t h e edges o f t h e bottom; some c r a c k s were c r o s s i n g

t h e seams and o t h e r s were o u t s i d e t h e seams, The t h i c k n e s s of t h e s h e e t s was 6.2 mrn, D w i n g t h e time when t h e c r a c k s a p p e a r e d no work was b e i n g c a r r i e d o u t on t h e r e s e r v o i r s ,

We have c a r r i e d o u t l a b o r a t o r y t e s t s on the b a s i c m e t a l and t h e s e r e s u l t s a r e compiled i n T a b l e I , A l l t h e t e s t e d samples had s e p a r a t e d i n t o l a y e r s p a r a l l e l t o t h e s u r f a c e o f t h e s h e e t .

6. On t h e c o n s t r u c t i o n p l a t f o r m d u r i n g t h e summer months welded r e s e r v o i r s of a n underground t y p e , of s m a l l

c a p a c i t y were completed. The b e l t s of t h e r e s e r v o i r s m a d e o f s t e e l , 6-8 mm. t h i c k n e s s had on t h e v e r t i c a l b u t t j o i n t s s o l i d l i n i n g s and, i n o r d e r t o i n c r e a s e t h e s t r e n g t h , b r a c e s and s t r e n g t h e n i n g b e l t s of double T beams were welded t o them. The welding was c a r r i e d o u t w i t h t h i n l y c o a t e d e l e c t r o d e s .

I n December, a t a n a v e r a g e t e m p e r a t u r e o f -43,50C0 d e l i v e r y t e s t s on t h e r e s e r v o i r s were c a r r i e d o u t . To t e s t t h e q u a l i t y o f t h e seams k e r o s e n e , under p r e s s u r e , was i n t r o d u c e d i n t o t h e s p a c e between t h e s o l i d l i n i n g and t h e b e l t , a s w e l l a s u n d e r t h e n o t c h a n g l e s . I n d i v i d u a l small d e f e c t s , p r o d u c i n g s m a l l k e r o s e n e s p o t s

,

were found,

The f u s e d up m e t a l , i n t h e s p o t s where the k e r o s e n e came t h r o u g h , was b e i n g c u t o u t by a hand c h i s e l . During t h e p r o c e s s of c u t t i n g o u t c r a c k s have a p p e a r e d . By h e a t i n g t h e d e f e c t i v e p l a c e s w i t h a welding t o r c h t h e number of c r a c k s h a s d e c r e a s e d , b u t some s t i l l remained.

D i r e c t l y a f t e r t h e welding-over of t h e c u t o u t s p o t s , s m a l l c r a c k s were observed s p r e a d i n g from t h e s u p e r - imposed s e c t i o n of t h e seam, which were immediately o b s e r v e d

The Chemical Composition and t h e hlechanical. Properties af the

S t e e l S h e e t s ( s e g m e n t s ) Frorn t h e Broken U p Bottom of t h e R e s e r v o i r

The P l a c e from wnere t h e Sample was Obtained From t h e segment on which a l a r g e c r a c k a p p e a ~ e d , From t h e segment on which a s m a l l c r a c k appeared

From tne segment which d i d n o t have any c r a c k ,

-

The T h i c k n e s s Composition

7;

M e c h m i c a l Properties of t h e S h e e t , Y i e l d S t ~ e n g t n at Tension kg/m. 46.0 47.7 47,% 46.1 5 4 , 8 5 9 , 7 I rnm

.

t

. 6.2

e

6 , 2 d e i a t i v e E l o n g a t i o n $ a I ii 15.5 I 20,O 2 4 , s 23.6 21,8 2 0 , 9

.

C 0.31 0 , 2 2 0 , 2 3 0,24 F 'tra@:30,05 0 , 0 7 6 0.6'75 0 , 0 7 5 C,045 0 , 0 4 5 - "

ni

n 0.35 6.27 5 0.034 0.040 0.044 0.040 0,G%3 0.040 Si 0 , s 0 , 9 8 0 , 4 5 0 , 4 4 0 , 5 l 0 - 4 8 !

'

"

"

!'

due t o t h e k e r o s e n e coming t h r o u g h t o t h e s u r f a c e o f t h e seam. S h o r t and h a i r - l i n e c r a c k s , a l m o s t c o m p l e t e l y i n v i s i b l e t o t h e naked e y e , were f o u n d a t t h e end of t h e weld seam. Sometimes t h e c r a c k s d i d n o t i m m e d i a t e l y a p p e a r A , s i n c e t h e k e r o s e n e would b u r n o u t u n d e r t h e w e l d i n g s p o t and i t would t a k e time f o r i t t o t r a v e l f r o m t h e o t h e r s e c t i o n s .

I n a d d i t i o n t o t h e l o n g i t u d i n a l c r a c k s a l o n g t h e seam, c r o s s s e c t i o n a l c r a c k s were sometimes o b s e r v e d which s p r e a d t o t h e b a s i c m e t a l a n d c r o s s e d t h e j u s t welded s e c t i o n o f t h e seam ( F i g . 2 ) . P r e h e a t i n g t h e welded s p o t s o v e r a c o n s i d e r a b l e s e c t i o n w i t h a w e l d i n g t o r c h d i d n o t p r o d u c e s u c c e s s f u l r e s u l t s . L o c a l h e a t i n g s o f t h e m e t a l b e f o r e w e l d i n g a l s o d i d n o t remove t h e p o s s i b i l i t y o f t h e a p p e a r a n c e of c r a c k s , b u t i n a d d i t i o n b r e a k s i n t h e b a s i c m e t a l on t h e b o r d e r s o f t h e z e r o i s o t h e r m s a p p e a r e d ; t h i s t y p e o f c r a c k a p p e a r e d more o f t e n n e a r t h e o v e r l a p p i n g searns which c o n n e c t e d t h e

l o n g i t u d i n a l l i n i n g w i t h t h e r h e s e r v o i r ( F i g , 3 ) , P r e h e a t i n g was d i s c o n t i n u e d due t o l i t t l e e f f e c t i v e n e s s .

7. A t t h e same p l a c e and d u r i n g t h e same p e r i o d of t i m e , on t h e i n c o m p l e t e d r e s e r v o i r s b r e a k s o c c u r r e d i n t h e l o w e r n o t c h a n g l e s , c o n n e c t i n g t h e b o t t o m of t h e r e s e r v o i r w i t h t h e f i r s t b e l t of t h e body. The b r e a k i n t h e n o t c h a n g l e was accompanied b y a s t r o n g r e p o r t s o u n d i n g l i k e a

was b e i n g done on t h e r e s e r v o i r s ,

The f o r m t i o n o f t h e c r a c k s f r e q u e n t l y began f r o m t h e b r e a k of t h e seam conr3.ecting t h e two segments o f t h e bottom s h e e t , This c r a c k c a r r i e d t o t h e c o r n e r , and l a t e r , g e n e r a l l y , b r o k e up o v e r t h e whole s p a c e ( F i g . 4 ) , Cracks were a l s o obseraved o v e r t h e whole of t h e c o r n e r which e x t e n d e d o v e r t o t h e segment s h e e t o f t h e b o t t o m , a c o n s i d e r a b l e

d i s t a n c e away from t h e seam,

8 , D u r i n g t h e w i n t e r on t h e same r e s e r v o i r s v e r t i c a l s u p p o r t s were b e i n g i n s t a l l e d by w e l d i n g them t o t h e body,

I n

o r d e r t o t i g h t e n t h e s u p p o r t s temporary s t r o n g c o r n e r s were welded t o t h e i n n e r s u r f a c e of t h e r e s e r v o i r b e l t .

During t h e moment of t h e a p e e x c i t a t i o n , f o r t h e s u p e r - i m p o s i t i o n o f t h e seam, c r a c k s a p p e a r e d on t h e b e l t s h e e t s . The f o r m a t i o n o f t h e c r a c k s was accompanied by a c h a r a c t e r i s t i c c r a c k l i n g n o i s e o Each t i m e two m u t , u a l l y c r o s s i n g c r a c k s a p p e a r e d , The d i r e c t i o n o f t h e c r a c k s i n

r e l a t i o n t o t h e welded c o r n e r w a s i r r e g u l a r ( F i g . 5, a a n d b ) , The l e n g t h o f t h e c r a c k s was 200-300 mm, and i n some c a s e s r e a c h e d up t o l M o The l e n g t h s of t h e m u t u a l l y p e r p e n d i c u l a r c r a c k s , a p p e a r i n g s i m u l t a n e o u s l y , were a p p r o x i m a t e l y e q u a l , C r o s s - l i k e c r a c k s o f a s i m i l a r n a t u r e have a l s o b e e n o b s e r v e d i n a n o t h e r c a s e . Durfng welding-over o f t h e c u t o u t d e f e c t i v e s p o t s , d e s c r i b e d i n c a s e No, 6 and c a r r i e d o u t a t a t e m p e r a t u r e of -45

--

- 5 7 * C 0 , f i n e

h a i r - l i k e c r a c k s were b e i n g formed and a n immediate b r e a k a l o n g t h e whole of t h i s seam a p p e a r e d d u r i n g t h e i n i t i a t i o n o f t h e w e l d i n g a few s e c o n d s a f t e r t h e s t a r t of the a r c ,

when t h e seam h a s n o t y e t had time t o be forlmed, S i m u l t a n e o u s l y , t h e r e a l s o a p p e a r e d a c r o s s s e c t i o n a l c r a c k i n t h e b a s i c m e t a l p a s s i n g t h r o u g h t h e h o t c r a t e r , o r more a c c u r a t e l y t h r o u g h t h e

s t a r t i n g s p o t o f t h e apt,

9, V e r t i c a l c y l i n d r i c a l r e s e r v o i r s f o r p e t r o l e u m p r o d u c t s o f c a p a c i t y 4690 M~ wepe b e i n g welded. The lower b e l t o f t h e r e s e r v o i r had t h r e e s t r e n g t h e n i n g l i n i n g s on each v e r t i c a l

seamo The m a t e r i a l was s t a n d a r d s t e e l o f mark C t - 3 ,

A t a t e m p e r a t u r e o f -25, -30°C. c r a c k s c r o s s i n g t h e seam a n d p a s s i n g between t h e l i n i n g s a p p e a r e d i n t h e f i n i s h e d welded b e l t s . The maximum c r a c k was of 1400

M

i n l e n g t h and t h e s p a c e between t h e e d g e s i n t h e r e g i o n o f t h e seam r e a c h e d up t o 1 0 mm. ( F i g , 6 ) . On t h e same r e s e r v o i r s t h e bottom b u t t

j o i n t s c o n n e c t i n g t h e s h o r t e d g e s of t h e s h e e t s o f 6 mm, t h i c k n e s s were s t r e n g t h e n e d b y a n a d d i t i o n a l l a y e r o f s u p e r - imposed m e t a l a l o n g a l e n g t h of a b o u t 80 mm. I n t h i s e a s e s e v e r a l c r a c k s were a l s o found, These c r a c k s s p r e a d a l o n g t h e t o t a l l e n g t h o f t h e r e i n f o r c e d s e c t i o n a s w e l l a s t o t h e b a s i c m e t a l o f t h e n e i g h b o r i n g s h e e t ( F i g . 7 ) ,

10. I n F e b r u a r y of 1945 a t a t e m p e r a t u r e o f -20°C, and a s m a l l wind ( n o t h i g h e r t h a n 2-3 s c a l e p o i n t s ) t h e w e l d i n g o f a v e r t i c a l c y l i n d r i c a l r e s e r v o i r o f 10.000 c a p a c i t y

f o r t h e s t o r a g e o f p e t r o l e u m was c a r r i e d o u t , F i v e c y l i n d r i c a l b e l t s o f 1 4 5 0

M

i n h e i g h t were a s s e m b l e d on t h e t a c k w e l d s . The v e r t i c a l seams w e r e w e l d e d o n l y o n t h e f i r . s t a n d s e c o n d l o w e r b e l t s . The w e l d i n g o f t h e f i r s t l o w e r b e l t t o t h e b o t t o m was c a r r i e d o u t i n t h e same d i r e c t i o n w i t h o u t t h e u s e o f a n o t c h a n g l e , a s i s u s u a l i n s u c h cases, b y two w e l d e r s . The w o l d e r s w e r e l o c a t e d a t a d i s t a n c e o f a b o u t two m e t e r s f r o m each o t h e r , One o f t h e w e l d e r s was i n s i d e o f t h e r e s e r v o i r a n d t h e o t h e r o n t h e o u t s i d e , The w e l d i n g was c a r r i e d o u t w i t h i m p o r t e d e l e c t r o d e s of mark E-6010;

t h e seam was a d o u b l e l a y e r o f 8 rum, i n h e i g h t , B o t h w e l d e r s w e r e d o i n g t h e f i r s t l a y e r , A t t h e a b o v e s t a t e d m e t e o r o l o g i c a l c o n d i t i o n s t h e i n n e r seam, b e i n g w e l d e d b y o n e o f t h e men c r a c k e d e x a c t l y o p p o s i t e t h e s p o t where o n t h e o t h e r s i d e o f t h e b e l t , c o n s i s t i n g o f a 14 rnm. t h i c k s h e e t , was t h e a r c o f t h e o t h e r w e l d e r . The c r a c k s p r e a d o v e r a l e n g t h o f 2 0 0 mrn, ( F i g , 8 ) , f o r m i n g a s l i t o f 0.5--0.7 mm, w i d e . The w e l d i n g was c o n t i n u e d a t a h i g h e r t e m p e r a t u r e and no b r e a k s o f a s i m i l a r n a t u r e h a v e o c c u r r e d , 11, D u r i n g t h e c o n s t r u c t i o n of r e s e r v o i r s many c a s e s o f c r a c k f o r m a t i o n i n t h e b a s i c m e t a l u s e d f o r t h e b o t t o m s were o b s e r v e d ; p a ~ t i c u l a r l y i n t h e s e c t i o n l o c a t e d o p p o s i t e t h e seam c o n n e c t i n g two n e i g h b o r i n g s h e e t s e g m e n t s ( F i g . 9). T h e s e c r a c k s h a v e a p p e a r e d a t a t e m p e r a t u r e o f -15°C. and l o w e r , a n d h a v e g e n e r a l l y o c c u r r e d w i t h o u t a n y o t h e r o u t s i d e

a c t i o n on t h e m a t e r i a l (Ref 7 ) ,

Cold B r i t t l e n e s s

As i s w e l l known, t h e m e c h a n i c a l p r o p e r t i e s of s t e e l , a s w e l l a s of o t h e r m a t e r i a l s , a r e d e p e n d e n t on t h e t e m p e r a t u r e a t which t h e y a r e worked o r t e s t e d , F i g e 1 0 shows a g r a p h

of t h e change i n t h e r e s i l i e n c y of low c a r b o n s t e e l a g a i n s t t e m p e r a t u r e , By l o w e r i n g t h e t e m p e r a t u r e a c o n s i d e r a b l e change i n t h e r e s i l i e n c y o c c u r s e T h i s phenomenon was named " c o l d B r i t t l e n e s s " .

I n l a b o r a t o r y impact t e s t s on n o t c h e d samples c o o l e d t o v a r i o u s t e m p e r a t u r e s , i n t e r m i t t e n t changes i n t h e r e s i l i e n c y were o b s e r v e d . T h i s s h a r p change i n t h e r e s i l i e n c y does n o t t a k e p l a c e a t a s t r i c t l y d e f i n i t e t e m p e r a t u r e , b u t a t some f a i r l y narrow i n t e r v a l of t e m p e r a t u r e s (5-15OC), I n

t h e l i m i t s o f t h i s t e m p e r a t u r e i n t e r v a l , some i n d i v i d u a l samples g i v e t h e h i g h e s t v a l u e s f o r t h e r e s i l i e r l c y v b u t some g i v e t h e l o w e s t ; i n t e r m e d i a t e v a l u e s a r e a l s o e n c o u n t e r e d , Below t h i s i n t e r v a l a l l t h e samples g i v e low v a l u e s .

The a v e r a g e v a l u e o f t h e t e m p e r a t u r e , c o r r e s p o n d i n g t o t h e i n t e r v a l of d i s p e r s i o n , we w i l l name a s t h e " c r i t i c a l t e m p e r a t u r e o f t h e c o l d b r i t t l e n e s s " ( F i g . 11). I t must b e n o t e d t h a t s t a t i c t e n s i o n t e s t s , b e n d i n g t e s t s and h a r d n e s s t e s t s , c a n n o t r e v e a l t h o c r i t i c a l temperature of t h e c o l d b r i t t l e n e s s , s i n c e t h e changes i n t h e y i e l d s t r e n g t h r e l a t i v e t o t h e e l o n g a t i o n and h a r d n e s s a r e u n i f o r m , a n d l e s s s h a r p t h a n t h e r e s i l i e n c y -

The c r i t i c a l t e m p e r a t u r e of t h e c o l d b r i t t A e n e s s i s m a i n l y d e p e n d e n t on t h e c h e m i c a l c o m p o s i t i o n o f t h e s t e e l , i t s c o n d i t i o n o f t r e a t m e n t ( i n p a r t i c u l a r , c o l d t r e a t m e n t ) , t h e t e n s i o n c o n d i t i o n s a n d t h e r a t e of t h e l o a d a p p l i c a t i o n ( i m p a c t ) . A c c o r d i n g t o t h e d a t a e x i s t i n g i n l i t e r a t u r e ( 4 ) t h e i n c r e a s e o f c a r b o n i n s t e e l i n c r e a s e s t h e u p p e r l i m i t o f t h e c r i t i c a l i n t e r v a l o f c o l d b r i t t l e n e s s i n t h e d i r e c t i o n of h i g h e r t e m p e r a t u r e s , and somewhat i n c r e a s e s t h e c r i t i c a l t e m p e r a t u r e of t h e c o l d b r i t t l e n e s s , The p r e s e n c e o f p h o s p h o r o u s , s u l p h u r , s i l i c o n and n i t r o g e n i n c r e a s e c o n s i d e r a b l y more t h e c r i t i c a l t e m p e r a t u r e o f t h e c o l d b r i t t l e n e s s , and p a r t i c u l a r l y t h e u p p e r l i m i t of t h e c r i t i c a l t e m p e r a t u r e i n t e r v a l . The e f f e c t s of t h e s e e l e m e n t s a r e i n c o m p a r a b l y l a r g e r t h a n t h a t of c a r b o n , I n t h i s s e n s e , p h o s p h o r e x e r t s a c o n s i d e r a b l y g r e a t e r e f f e c t , p a r t i c u l a r l y i n t h e f i r s t s t a g e s o f i n c r e a s e i n i t s c o n t e n t s . T h e r e f o r e , Thomas and Bessemer s t e e l s , which h a v e a h i g h e r c o n t e n t of p h o s p h o r o u s and s u l p h u r , b e l o n g t o t h e

s t e e l s w i t h a hip$er c o l d b r i t t l e n e s s , A c c o r d i n g t o o u r o b s e r v a t i o n s Bessemer s t e e l i n some c a s e s has a n u p p e r l i m i t f o r t h e c r i t i c a l i n t e r v a l o f t h e o r d e r of t 10°C. a n d a

c r i t i c a l t e m p e r a t u r e o f c o l d b r i t t l e n e s s of t h e o r d e r of -5Oc*

p r o p e r t y o f phosphorous and s u l p h u r t o l i q u a t e l e a d s t a t h e f a c t t h a t i n c e r t a i n s p o t s o f t h e r o l l e d s h e e t s , beairis o r t u b e s , t h e s e e l e m e n t s can be found i n c o n s i d e r a b l y

l a r g e r q u a n t i t i e s t h e n i s s t a t e d i n t h e s p e c i f i c a t i o n s , The c o l d t r e a t m e n t of t h e m e t a l , produced b y t h e a c t i o n o f t e n s i o n , compression, b e n d i n g and impact g c n e r a l l y d e c r e a s e s t h e t o u g h n e s s . The c r i t i c a l t e m p e r a t u r e o f t h e c o l d b r i t t l e n e s s of c o l d t r e a t e d s t e e l i s d i s p l a c e d i n t o t h e r e g i o n o f t h e h i g h e r t e m p e r a t u r e s , S h r i n k i n g t e n s i o n s , a s i s shown b y t h e o r e t i c a l c o n s i d e r a t i o n s ( 4 ) and e x p e r i m e n t a l i n v e s t i g a t i o n s ( 5 ) , do n o t d i r e c t l y i n f l u e n c e t h e c r i t i c a l t e m p e r a t u r e of t h e c o l d b r i t t l e n e s s . However, t h e a c t i o n of i n n e r t e n s i o n s p r o d u c e s a d i f f e r e n t e f f e c t , a s w i l l b e p o i n t e d o u t l a t e r o The r a t e o f t h e d e f o r m a t i o n of m e t a l e x e r t s a n i n f l u e n c e on t h e v a l u e o f t h e c r i t i c a l t e m p e r a t u r e of t h e c o l d b r i t t l e n e s s .

F,

Vitman ( 8 ) e s t a b l i s h e d , t h r o u g h h i s i n v e s t i g a t i o n s , t h a t b y i n c r e a s i n g t h e r a t e o f d e f o r m a t i o n t h e c r i t i c a l t e m p e r a t u r e o f t h e c o l d b r i t t l e n e s s i s d i s p l a c e d i n t h e d i r e c t i o n of t h e r e g i o n o f h i g h e r t e m p e r a t u r e s , The r e l a t i o n between the c r i t i c a l t e m p e r a t u r e Tk and t h e r a t e o f t h e d e f o r m a t i o n v i s e x p o n e n t i a l , gnd c a n be e x p r e s s e d b y a n e q u a t i o n o f t h e f o l l o w i n g form:

Thus a t a d e f i n i t e t e m p e r a t u r e , n e a r t c i t h e c r i t i c a l t e m p e r a t u r e o f t h e c o l d b r i t . t . l e n e s s , steel icoses t o a

c o n s i d e r a b l e d e g r e e , i t s p 1 a s t i . c p r o p e r t i e s , But i t i s t h e s e p r o p e r t i e s t h a t the d e s i g n e r t a k e s inLo a c c o u n t when s e l e c t i n g t h e t y p e of s t e e l f o r a g i v e n c o n s t ~ ~ u c t , i o n , I f t h e c r i t i c a l t e r n p e r a t w e d o e s n o t e x c e e d t h e w c r k i n g t e m p e r a t u r e o f t h e c o n s t r u c t i o n , a n d i n p a r t i c u l a r t h e t.empelaature a t which t h e a s s e m b l y a n d w e l d i n g a r e c a r r i e d o u t , t h e n thig p r o p e r t y i s of

no p a r t i c u l a r t e c h n i c a l i n t e r e s t , 1,lany Y t e e l s , amongst them

open- h e a r t h , h a v e a c r i t i c a l t e m p e ~ a t u ~ e of ccr l d b ~ i t , t l e n e s s ( d e t e r m i n e d u n d e r l a b o r a t o r y c o n d i t i o n s ) e q u a l t o - 3 0

-

- 4 0 ° ~ , . The t o t a l e f f e c t of o t h e r f a c t , o r s ( c o l d w o r k i n g , i m p a c t ,

wind s t r e n g t h e t c a ) no d o u b t , I n c r e a s e t h e c r i t i c a l t e n i p e r a t u r e and t h e s t e e l becomes b r i t t l e , T h i s beconies e v i d e n t from t h e

c a s e s of destl.uc t i o n a t I - e l a t i v e l g h i g h ternpepa Lures ( a b o v e ~ 2 5 ~ t 4 ' ) which we h a v e c i t e d .

The A n a l y s i s o f t h e Causes o f t h e D e c o m p o s i t i o n - --- o r S t e e l . i n Cold ..-.-

VJea t h e r

-

The c o l d b r i t t l e n e s s i s o n l y one of t h e c o n d i t i o n s ~ e s p o n s i b l e f o r t h e b r e a k - u p o f t h e m e t a l . The b r i t t l e n e s s o f m e t a l b y i t s e l f w i l l n o t brrbing a b o u t , a breakdown, O t h e r i n n e r , o r o u t e r f a c . t o r s a l t e r i n t o I t , w h i c h u t i l i z e t h e r e s u l t i n g b r i t t l e c o n d i t i o n of t h e r n c t a l b p o u g h t a b o u t b y t h e l o w e r e d t e m p e r a t u r e , t h u s p r o d u c i n g a brealrdown F r l t,'l-ie c o n s t r u c t i o n ,

To t h e numbel- of s u c h c a u s e s Isle can a s s i g n khe i m p a c t l o a d , s h r i n k a g e t e n s i o n , momentary forma t i o n o r r.edis t r i b u t i o n of l o c a l t e n s i o n s , O t h e r c a u s e s , of c o u r s e , are p o s s i b l e , 1) A s t r o n g i m p a c t a l o n g t h e m e t a l l i c c ~ n s t r u c t i o n , found i n a s t a t e of c o l d b r i t t l e n e s s q u i t e o f t e n w i l l r e s u l t in A t h e f o r m a t i o n o f c r a c k s , A t t h e c u t t i n g o u t of d e f e c t i v e s p o t s b y a c h i s e l t h e f o r m a t i o n o f b r e a k s o r c r a c k s i s o b s e r v e d /

sometimes n o t even a t t h e s p o t s where t h e blow i s s t r u c k , b u t a t a c o n s i d e r a b l e d i s t a n c e f r o m i t , The s t r i k i n g wave, b e i n g

i n s u f f i c i e r tlg q t r o n g t o b r e a k down t h e s p o t n e a r t h e blow, p r o d u c e s a breakdown i n t h e s p o t s where f a v o r a b l e f o r t h i s

c o n d i t i o r s s r e found. !Yelding seams p r o d u c e d w i t h t h i n l y c o a t e d e l e c t r o d e s , a s w e l l a s seams h a v i n g non-fused s p o t s , o f t e n

b r e a k down, 'Nelded seams o f t e n b r e a k down b y a d i r e c t a c t i o n o f t h e i m p a c t - T h i s i s n o t o n l y t r u e o f s e a m s made w i t h t h i n l y c o a t e d e l e c t l - o d e s b u t a l s o w i t h t h i c k l y coat.ed e l e c t r o d e s The f o r c e of t h e impact l o a d can b e i l l u s t r a t e d b y tize t y p e o f

d e s t r u c t i o n d e s c r 2 i b e d i n c a s e 1,

2 ) I n some o f t h e c a s e s descztibed a b o v e , breakdowns of t h e m e t a l (of' r e s e r v o i r s , a n d e v e n o f T b e a m s ) h a v e o c c u r r e d w i t h o u t a n y o u t e r f o r c e a c t i o n s ,

The o n l y e x p l a n a t i o n which can b e p r e s e n t e d a s a n i n i t i a l w o r k i n g h y p o t h e s i s i s t h e a s s u m p t i o n t h a t t h e c a u s e ~ f s u c h breakdowns of c o l d b r i t t l e r n e t a l i s clue tc; i n n e r s t l r i n k a g e t e n s i o n s .

T h i s can b e s u p p o r t e d b y t h e f o l l o w i n g c o n d i t i o n s : ( a ) i n a s s e m b l i n g r i v e t t e d e o n s t . r u c t i o n s , where a n y c o n s i d e r a b l e s h r i n k i n g t e n s i o n i s a b s e n t , s u c h s p o n t a n e o u s breakdowns a r e n o t o b s e r v e d ; a p p a r e n t l y t h e r e a r e no s p e c i a l t e c h n o l o g i c a l f e a t u r e s which would d i s t i n g u i s h t h e w e l d i n g c o n s t r u c t i o n c a r r i e d o u t u n d e r w i n t e r c o n d i t i o n s from t h o s e c a r r i e d o u t a t norinal t e m p e r a t u r e s ( 6 ) ; ( b ) a t a low t e m p e r a t u r e t h e seams breakdown i r r e s p e c t i v e whether t h e y were made i n w i n t e r o r

i n

summer

3 ) During t h e p r o c e s s o f s u p e r i m p o s i t i o n of t h e seam

a r e d i s t r i b u t i o n i n t h e i n n e r t e n s i o n s t a k e s p l a c e , If a t t h i s

time t h e m e t a l i s found a t a t e m p e r a t u r e lower t h a n t h e c r i t i c a l i n t e r v a l , t h e dynamics o f t h e r e d i s t r i b u t i o n , o r t h e f o r m a t i o n of i n n e r t e n s i o n s a r e c a p a b l e of b r i n g i n g a b o u t a breakdown i n t h e f u s e d o r b a s i c m e t a l , Proof of t h i s i s p r e s e n t e d i n t h e e a s e s of breakdown described under 8 and 1 0 ,

C o n c l u s i o n s 1, S t r u c t u r e s welded a t low t e m p e r a t u r e s , a t w h i c h a t r a n s i t i o n o f t h e b a s i c and superimposed m e t a l i n t o t h e c o l d b r i t t l e n e s s r e g i o n i s p o s s i b l e , must r e c e i v e a minimum o f s h r i n k a g e s t r a i n s o E f f i c i e n t c o n s t r u c t i o n , a c o r r e c t p o s i t i o n of t h e seams a n d a minimum of t h e i r c r o s s s e c t i o n s w i l l f a c i l i t a t e t h e s o l u t l o n o f t h i s problem.

However, t h e m a j o r c o n s i d e r a t i o n s s h o u l d be p a i d t o t h e t e c h n i c a instructions n t h e methods of' a s s e m b l y a n d w e l d i n g . I n t h e a s s e m b l y of s h e e t c o n s t r u c t i o n s , f o r example

l a r g e r e s e r v o i r s , i t i s u s e f u l t o c a r r y o u t t h e a s s e n b l y f o r w e l d i n g n o t w i t h t a c k welds b u t w i t h t h e a i d o f s p e c i a l

a u x i l i a r y a s s e m b l i e s

,

which s u p p o r t t h e mounting e l e m e n t s b y f r i c t i o n and which can b e rnoved a s t h e w e l d i n g p r o c e e d s , 2 . A t p r e s e n t s t r u c t u r a l s t e e l s a r e b e i n g marked a c c o r d i n g t o t h e i r m e c h a n i c a l c h a r a c t e r i s t i c s o b t a i n e d from s t a t i c t e s t s ( y i e l d s t r e n g t h , r e l a t i v e e l o n g a t i o n ) , and t o u g h n e s s o b t a i n e d a t room t e m p e r a t u r e , The s p e c i f i c a t i o n s a l s o g i v e t h e d a t a on t h e c h e m i c a l composition. However, t h e s e d a t a a r e i n s u f f i c i e n t t o d e t e r m i n e t h e p r o p e r t i e s of s t e e l a t low t e m p e r a t u r e s , I t i s e s s e n t i a l t o i n t r o d u c e t h e problerr~ o f compulsory i m p a c t t e s t s a t low t e m p e r a t u r e s on s t e e l s which

a r e u s e d f o r i m p o r t a n t m a s s i v e c o n s t r u c t f o n s ( b r i d g e s , r e u e r ~ v o l r e , m e t a l l u r g i c a l c o n s t r u c t i o n s e t c , )

I n o r d e r t o r e d u c e t h e q u a n t i t y of t h e r e s t samples, i t would be s u f f i c i e n t t o c a r r y o u t ~ o u g h n e s s t e s t s a t rouri t e m p e r a t u r e and a t a t e m p e r a t u r e o f

-

40°C. I f t h e r e s u l t s of t h e s e two t e s t s ( t h e a v e r a g e o f two

-

t h r e e samples f o r e a c h t e m p e r a t u r e ) do n o t d i f f e r g r e a t l y , then t h e s t e e l c a n b e u s e d f o r s t r u c t u r e i n r e g i o n s , where 2 c o i d ten?peraat.urt: p r e d o m i n a t e s , The o t h e r s t e e L s w i t h a h i g h ;ialue o f the c r i t i c a l t e m p e r a t u r e f o r c o l d b r i t t l e n e s s can b e u t i l i z e d i n r e g i o n s where t h e c l f l n a t i c c o n d i t i o l i s a r e more favol-nblr.,

3. I t i s i m p o s s i b l e t o s t a t e t h e l i m i t i n g t e m p e r a t u r e , b e l o w which w e l d i n g must n o t be c a r r i e d o u t , , i f ' %he d a t a o n t h e c o l d b r i t t l e n e s s o f t h e s t e e l i n q u e s t i o n i s n o t a v a i l a b l e , With no c o n t r o l f o r t h e c o l d b r i t t l e n e s s , t h e p o s s i b i l i t y e x i s t s t h a t v a r i o u s s m e l t i n g s t e e l s f r o m d i f f e r e n t f a c t o r i e s w i t h s i m i l a r s t a n d a r d c h a r a c t e r i s t i c s b u t w i t h a c r i t i c a l t e m p e r a t u r e foxa t h e c o l d b r i t t l e n e s s v a r y i n g f r o m -60°C. t o - 1 0 " ~ . w i l l b e u s e d , I n t h e p r e s e n t a t i o n o f d a t a on t h e c o l d b r i t t l e n e s s , i t would be e a s y t o e s t a b l i s h t h e l i m i t i n g t e m p e r a t u r e b e l o w which w e l d i n g m u s t n o t be c a r r i e d o u t . I t must b e a p 1 , r o x i m a t e l y

l o 0

h i g h e r t h a n t h e u p p e r l i m i t o f t h e c r i t i c a l i n t e r v a l o f t h e c o l d b r i t t l e n e s s , 4, W e l d i n g u n d e r w i n t e r c o n d i t i o n 3 i n s p i t e o f a l l i t s p r a c t i c a l i m p o r t a n c e p r e s e n t s a s e r i o u s s n d d i f f i c u l t p r o b l e m , +J A t t e n t i o n m u s t b e g i v e n t o t h e s o l u t i o n o f t h i s p r o b l e m b y t h e s c i e n t i f i c e x p e r i m e n t a l o r g a n i z a t i o n s , Moreover, n o t a s i n g l e example of a breakdown o r u n u s u a l b e h a i ~ i o u r o f m e t a l a t w e l d i n g u n d e r w i n t e r c o n d i t i o n s must r e m a i n w i t h o u t s c i e n t i f i c i n v e s t i g a t i o n a n d s t u d y ,

B i b l i o g r a p h y G. A l a t y r t b s e ~ r . V e s t n i k o f t h e M e t a l I n d u s t r y , 1939, No. 10-11. E.V. K u d r y a v t s e v . V e s t n f k o f t h e M e t a l I n d u s t r y , 1 9 4 0 , No. 1 0 , From t h e d a t a o f t h e A s s e ~ b l y

-

Welding T r u s t .

E O N . Davedenkov. The problem o f i m p a c t i n m e t a l l u r g y , P u b l i s h e r s of t h e Academy of S c i e n c e , U . S , S , R . 1 9 3 8 , E,V. K u d r y a v t s e v . J o u r n a l o f T e c h n i c a l P h y s i c s , Vol, X V I .

No. 11, 1946.

K O O l i f i r e n k o and V . Vologdin, S t r u c t u r e arici m e c h a n i c a l p m o p e r t i e s of e l e c t r o - w e l d e d seams c a r r i e d o u t a t low t e m p e r a t u r e , 193 6 , V , D . T a r a n . The r e p o r t of t h e G e n e r a l Webding L a b o r a t o r y , 1 9 3 9 , F,F, Vitman, t h e J o u r n a l o f T e c h n i c a l ' ~ h ~ s i c s , Vol, X V I I , No. 1, 1947,

Pig. 1

crack

1

-

the preheating ieothern; 2

-

crack; J

-

welded over

eeaa

r i g . 2

1

-

crack; 2

-

the welded over epot; J

-

the croee eectional crack;

4

-

prevloue eeen

r i g .

4

1

-

crack: 2

-

notch corner;

J

-

the sheet of the segment ring;

4

-

the sheet of the bottom

1

-

welded corner: 2

-

the spot where the eeam begins

pig.

7

1

-

reinforced butt seam; 2

-

butt aeam

1

-

corer plate: 2

-

the rer- t i c a l butt seam;

3

-

crack

Temperature degrees C Fig. 10

The graph of change i n the r e s i l i e n c y o f carbon s t e e l s again8 t temperature

1

-

crack: 2

-

the sheet o f tb

se-nt ring:

3

-

the bottom plane

Temperature degrees C r i g . 11