THE EFFECT OF HEAT TREATMENTS ON THE BEHAVIOR

SISOM – 2004, BUCHAREST, 20-21 May 

METHODS FOR THE EVALUATION OF THE RESIDUAL 

STRESS LEVEL IN MULTIPLE PASS WELDING 

Marius Gabriel PETRESCU, Niculae Napoleon ANTONESCU, Ion NAE, Adrian Catalin DRUMEANU 

Petroleum-Gas University of Ploiesti, pmarius@mail.upg-ploiesti.ro 

Abstract: The presence of the residual stresses greatly influences the 

reliability of the welded structure. That is why it is necessary to know the 

level of these stresses and to reduce them as much as possible. The paper 

present two methods for the evaluation of the residual stresses level in the 

butt welds of the cylinder type pieces; the obtaining results can be extended 

to the welded joints of the flat semi-products. The welding operations are 

accompanied by the volume variations of the pieces that are welded; these 

variations occur in all levels (under-microscopic, microscopic, 

macroscopic). But they do not occur freely – that is simultaneously and 

uniformly in all the micro-volumes or the macroscopic parts of the products 

– they occur with breaks on because the variations that occur in some of 

these micro-volumes or parts prevent the free variation of the near variations 

and vice versa. So, any fraction of the volume modification is achieved 

through a permanent plastic deformation and the others remain under the 

form of a temporary elastic deformation that will be coupled with a residual 

stress. 

Key Words: residual stresses, welded structure, welded joints 

1. INTRODUCTION 

Due to the reheating of the near fusion line zones in the moment the successive layers are deposited 

some complex phenomena occur; because of the thermal and mechanical accumulations in certain zones of 

the base metal and of the previously deposited layer. When depositing multiple layers the structural 

heterogeneousness in HAZ of the previously deposited layers is strengthened. 

From the mechanical point of view, while the posterior layers are deposited, all zones that are heated 

over the stress relieving temperatures (specific to the material), will be released and in the others the residual 

stresses will be overlapped on those caused by the previously deposited layers. The residual stress of the 

latest layers will be higher due to the constriction coming out from the previous deposits. 

The presence of the residual stresses greatly influences the reliability of the welded structure. That is 

why it is necessary to know the level of these stresses and to reduce them as much as possible. The paper 

presents two methods for the evaluation of the residual stresses level in the butt welds of the cylinder type 

pieces (shell rings). Those two methods were used in order to emphasize the influences of the technological 

process over the interior stresses that are produced in the cylinder pieces.

Marius Gabriel PETRESCU, Niculae Napoleon ANTONESCU, Ion NAE, Adrian Catalin DRUMEANU 372 

2. METHODS 

The paper [2] presents the Sachs method for the calculation of the residual stresses occurring in the 

annular section cylinder type pieces. In order to determine the tangential residual stress a longitudinal section 

is made in the shell ring measuring its exterior diameter perpendicularly to the section before (D 0 in mm) 

and after (D 1 in mm) cutting (figure 1). 

Figure 1. Sectional ring (Sachs method) 

Figure 2. The turning off method. 

In order to express the maximal value of the tangential remanent stress according to the exterior fibre 

of the shell ring, in the paper [3] there is proposed the following calculation relation: 

σ = 

1 

E 

2 

−µ ⋅s⋅ ( D0 D1 

1 1 

− ) [N/mm 2 ] (1) 

where: s is the the thickness of the shell ring, in mm; E – the longitudinal elasticity module, in N/mm 2 

(for steel E = 2,1 * 10 5 N/mm 2 ); µ - the Poisson coefficient (for steel µ = 0,3).

373 

Methods for the evaluation of the residual stress level in multiple pass welding 

The second method (the turning method) consists in cutting a number of rings out of the same sample. 

One of these will remain complete and the others will be turned off, the thickness of the material (t) which is 

turned off (differs to each ring) either from the exterior of the ring or from the interior (figure 2). The steel 

ring realized is cut in a total opposite point to the point in which is calculated the value of the σ stress. For 

each case σ is calculated using the relation (1) and taking into account that the obtained value which is 

obtained value of the residual stress at the distance t from the surface of the shell ring (when the interior 

turning occurs the sign of σ is changed, as the relation (1) gives the values for the exterior fibre, the values 

for the interior fibre are supposed to be equal in module and of opposite sign). 

3. EXPERIMENTAL RESEARCH 

For the study there was used a steel sheet semi-product R 510 – STAS 2883/2-91 having the thickness 

s = 12 mm, from which there were made by rolling and longitudinal welding, 3 shell rings having the form 

and the dimensions presented in figure 3. 

For the longitudinal welding there was used the procedure SE: covered electrodes Nibaz 65 having the 

diameter of 2,5 and respectively 3,25 mm; I S = 120 A; U a = 24 V; E L = 15000 … 17000 J/cm. The welded 

joint was realized by keeping to the succession of the stages presented in the figure 3. 

Figure 3. The shell rings for the study 

The second shell ring was submitted to a thermal stress relieving treatment (t î = 580 0 C; τ m = 90 min) 

and the third shell ring was submitted to a new rolling (calibration). 

From those produced shell rings there were assayed rings with the width of h = 20 mm. 

In order to establish the maximal values of the stresses from the shell rings in the 3 variants of 

preparation, three rings of each sample were cut in a total opposite diametric point of the welded joint using 

a face and side cutter having the width of 2 mm. The measuring results (according to the methodology 

already presented), as average of the three values are presented in the table 1 (rings no. 1 of the samples 1, 2 

and 3). 

In order to establish the distribution of the stresses on the thickness of the 3 samples there was applied 

the turning method. The results are presented in the table 1 and in the figures 4, 5 and 6.


4. CONCLUSIONS 

Analyzing the results of the research presented at this point the following may be concluded: 

- when using the multiple pass welding of the steels, the successive layer deposition of filler 

material has favorable effects on the level of the residual stresses in the welded joint the level of 

the residual stresses goes down). This phenomenon is explained through the reannealing effect 

produced by the layers which are deposited over the previously deposited layer; 

Table 1. The distribution of the stresses on the thickness of the samples 

No. 

1 

2 

Sample characteristics 

Welded / without stress 

relieving 

Welded / Stress 

relieved 

3 Welded / re-rolled 

Ring Type of turning off 

σ ext / int 

D 

no. and t values, mm 

0 mm D 1 mm t 

N/mm 2 

1 Not turned 250.320 250,752 12 19,0591 

2 In the interior t = 2 250,285 250,642 10 -13,1328 

3 In the interior t = 4 250,755 250,983 8,1 -9,74577 


5 In the exterior t = 2 246,295 246,796 10,2 19,4009 

6 In the exterior t = 4 242,312 242,985 8 17,9740 

1 Not turned 250,265 250,502 12 10,4687 






1 Not turned 250,292 250,634 12 15,0972 




5 In the exterior t = 2 246,203 246,495 10 11,1034 


25 

20 

15 

10 

sigma, N/mm2 

5 

0 

-5 

0 2 4 6 8 10 

12 

-10 

-15 

-20 

s, mm 

Figure 4. The distribution of residual stresses on the thickness of shell ring no. 1.

375 

Methods for the evaluation of the residual stress level in multiple pass welding 

20 

15 

10 

sigma, N/mm2 

5 

0 

-5 

0 2 4 6 8 10 

12 

-10 

-15 

-20 

s, mm 

Figure 5. The distribution of residual stresses on the thickness of shell ring no. 2. 

20 

15 

10 

sigma, N/mm2 

5 

0 

-5 

0 2 4 6 8 10 

12 

-10 

-15 

-20 

s, mm 

Figure 6. The distribution of residual stresses on the thickness of shell ring no. 3.


- the stress relieving heat treatment after the welding process has favorable effects; that is the 

decreasing of the residual stress level in the welded joint; it can be noticed that in the exterior 

fibre, the stress relieving produced stresses having the opposite sing to the residual stresses, of 

compression respectively which can have favorable effect during the exploitation, too; 

- the application of the rolling has favorable effect (as the stress relieving) on the level of the 

remanent stresses due to the welding operation. 

REFERENCES 

1. ***ASME,1992 – Boiler and Pressure Vessel Code, Section VIII, Division I, American Society of Mechanical Engineers, New 

York, NY 

2. MOCANU D.R., Experimental analyzing of the stresses, vol II, Editura Tehnica, Bucuresti, 1977. 

3. *** Development of High Collapse Casing, HT-95H.S, Nipon Steel Co, Tokyo, June, 1979. 

4. PETRESCU M.G., Cercetări privind materialele si tehnologia de executie specifice rezervoarelor sferice pentru produse 

petroliere, Ph.D. thesis, Ploiesti, 1997.

THE EFFECT OF HEAT TREATMENTS ON THE BEHAVIOR

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