HAZ Thermocycle and Structure Simulation
Combined computer and Gleeble simulation technique
permits quick evaluation of weld process alternatives
BY Ft. A. MUELLER, D. G. HOWDEN AND F. B. S I M M O N S
ABSTRACT. During the development
of an automatic gas metal-arc welding (GMAW) machine, high speed
welds were made in steel at 60 i p m .
The attendant low heat input created
a heat-affected zone (HAZ) having
thin, isolated hard zones. In order to
utilize high welding speeds, this study
was made on ways to eliminate or
prevent the HAZ hard zone formation.
The use of preheat, higher heat input, and a postweld heat treatment all
could reduce the HAZ hardness; however, for a variety of reasons these
methods were undesirable. In-line
heat treating, using an auxiliary heat
source following the main welding
arc, could prevent hard zone formation by altering the continuous c o o l ing curve to obtain low cooling rates
that permit diffusion controlled
austenite decomposition to occur before subsequent cooling below the
Ms. Another related technique, the
use of two welding arcs, was c o n sidered also. An empirical approach
was deemed too costly; therefore, a
computer simulation technique was
devised. The simulation technique
and its rationale are the subject of this
paper.
A two dimensional heat flow equat i o n involving the basic w e l d i n g
parameters and material properties
was selected for the simulation. A
realistic heat input efficiency factor
was used to calibrate the equation to
the welding m a c h i n e . T h e o r e t i c a l
time-temperature curves were generated simulating the HAZ tempera-
R. A. MUELLER and D. G. HOWDEN are
associated with Battelle Columbus Laboratories and F. B. SIMMONS is associated with Brush Beryllium Corporation.
Paper was presented at the 51st AWS
Annual Meeting held at Cleveland, Ohio,
during April 20-24, 1970.
ture cycles. Curves were generated
that simulated the weld centerline and
five additional positions located in the
HAZ.
Auxiliary heating curves were
generated and evaluated. Evaluation
criteria were based upon a predetermined relationship between the cooling rate at 900 F and the hardness of
Gleeble specimens. It was found that:
1. T h e h e a t i n p u t n e c e s s a r y t o
achieve the desired hardness reduction was so great that c o m p l e t e
remelting of the weld would have occurred.
2. The combined heat input of two
arcs would achieve a modest hardness reduction.
Neither of the approaches would
have reduced the HAZ hardness to
desirable levels; therefore, further
" G l e e b l e " s i m u l a t i o n s were performed with the result that if an auxiliary heat source arrested the HAZ
temperature at 1000 F for 6 sec, the
HAZ hardness would be at a desirable level.
The technically significant portion
of this work is the simulation technique, since it affords a method for
evaluating welding processes and
parameters without the need for extensive experimental equipment and
costly empirical data.
Background
A special purpose automatic GMA
welding machine was used to butt
weld thin carbon manganese steel
parts. The weld was m a d e with two
passes at a speed of 60 i p m . During
the development of the welding techniques problems arose due to the
creation of thin high hardness zones
(Re 50-52) in the HAZ of the welds.
The hard zones were caused by the
attendant high HAZ cooling rates. Due
to the end use of the product, the hard
zones were undesirable, a hardness
limit of Rc25 being the m a x i m u m desired. This study was made to determine methods for either eliminating
or preventing the HAZ hard zone formation.
For a variety of technical and economic reasons, the use of pre-heat,
the use of a higher heat input, and the
use of separate postweld heat treatments were undesirable even though
these methods could probably
achieve the desired hardness reduction. Therefore, the study c o n centrated on the two following hardness reduction methods:
1. In-line heat treating. If sufficient
auxiliary heat were to be added after
the weld had solidified, but before the
austenite had transformed, the cooling rates, hence hardness, of the HAZ
probably could be reduced.
The auxiliary heat, however, should
not be so high as to cause remelting
of the metal.
2. Multiple arc welding. The total heat
input of two welding arcs from two
weld passes could be sufficient to
achieve slow HAZ c o o l i n g rates,
hence prevent extensive martensite
formation.
With the first method, the auxiliary
heat might be supplied by an oxyacetylene burner which travels behind the welding electrode at the
same speed. The welding head of the
automatic welder was so designed
that with moderate modifications an
auxiliary heat source could be placed
11/2 to 2 in. behind the welding electrode. Likewise a second electrode
could be mounted VA to 2 in. behind
the main electrode to weld the second pass simultaneously with the first
pass, i.e., multiple arc welding. This
latter approach has an added a d vantage of decreasing the total joint
fabrication time.
In order for the first method of auxiliary heating to be successful, i.e.,
avoid the formation of martensite, the
WELDING RESEARCH SUPPLEMENT!
411-s
temperature of the bulk of the austenitic portion must not fall below the
Ms before t h e a d d i t i o n a l heat is
applied. If the arc is traveling at 60
ipm and the auxiliary heat source is
exactly 2 in. behind the welding electrode, then 2 sec will elapse before
the auxiliary heat source passes over
any given spot on the weld. Therefore,
in those 2 sec, the temperature of a
given spot must not fall below the
martensite start temperature (Ms)
which was known to be about 725 F.
One technique for determining if
the temperature of the HAZ has fallen
below the Ms in the VA to 2-in. distance, or 2 sec time interval for the example previously cited, involves placing thermocouples in the HAZ of a test
weld and generating the true cooling
curves. These curves could then be
examined for the desired information. This would have been time consuming and expensive in that a rather
elaborate experimental setup would
have been required. Also, any subsequent process alterations would
have to be studied in the same manner. Therefore a second technique
was selected. It involved the use of a
calibrated mathematical simulation to
provide the desired information. This
technique and its results are presented in the following sections.
Position of curves relative to
center line of weld
—
^Centerline 8 0.03 inch
2800 -
r * \ ^ 0 . 0 4 inch
2400
T " " " " " \ . 0 . 0 5 inch
1 / / 0 . 0 6 inch
y
/ / 0 . 0 8 inch
-
Volts
Amps
Speed
Efficiency
Kjoules/m.
2000
Cl)
I 600
3
—
n
CD
CL
b
I200
-
]«
f\
f \ l
\1
=
26
=
348
= 6000
= 0.80
=
7.2
Cooling Rates,
0.04
F/sec
Center Line 0 0 3
985.7. 967.0
T(I300) = 1050.6
321.4 322.0
T( 900) = 325.9
0.05 0.06
907.4 8 4 5 . 5
318.0 3 1 4 . 8
0.08
571.9
300.5
Gleeble sample 2 9 9 F/sec
Hardness
Rc 40
800
--
400
1
1
1
1
1
1
10
12
1
1
Time, sec
Fig. 1 — Typical thermal cycles based on a 0.80 thermal efficiency factor
2700
2600
Technical Approach
The general approach for simulating the in-line heat treating was
as follows.
A heat flow equation was selected
to generate theoretical HAZ heating
and cooling curves. The curves, which
were calculated and plotted using a
digital c o m p u t e r , w e r e then calibrated to the actual heating and cooling curves of a test weld. The calibrated equation was then used to
simulate various weld process alterations designed to reduce the HAZ
hardness. The more attractive
process alterations were then tested
using Gleeble specimens to verify that
they would indeed produce a low
hardness HAZ zone.
There are several equations which
can be used to calculate weld metal
a n d / o r HAZ c o o l i n g curves. The
equation selected for this work was
developed by Tall (Ref. 1). It is a two
dimensional heat flow equation which
best fits the heat flow of the weld.
T = Qp [ko ( x v r ) ] exp ( - \ v £ )
2500
2200
j
3
o 2000
CD
1
L_.
1800 —
1
t
1700
1600
I500
1300
1973
/
E 1900
Where T = temperature of any point
in the weld area at any time (t). Note
also that T = T-To where the pre-heat
(To) is zero.
412-s | S E P T E M B E R
J
J
aT2IOO
I400
K = thermal conductivity
X = SP/2K where S = specific heat
and P = density
J
2300
(1)
2Kh
1
2400
I
i?nn
0
0.1
I
I
0.2 0.3
I
0.4
1
1
1
0.5 0.6 0.7
!
0.8
1
20
14
1
0.9
E f f i c i e n c y Factor
Fig. 2 — Peak temperature of 0.04 in. cycle as a function of efficiency
1
1
1.0 I.I
£ = x-vt where x = distance behind
heat source, v = travel speed and
t = time
ko = Modified Bessel function of second kind, zero order
r = V £ 2 + y2 where Y = distance
from weld centerline
h = Plate Thickness
Qp =Total heat input including an
efficiency factor.
The terms, £ and r, represent the
mathematical terms necessary to calculate the temperature at any point in
the HAZ, i.e., some point other than
the weld centerline. These latter t e r m s
have the effect of translating the X-Y
coordinate system from the plate to
the torch which permits one to calculate the temperature distribution
about the arc in an X-Y plane.
The term, Ko, is a modified Bessel
function of the second kind, zero
order, which is used to provide the
desired solution to the differential
equation from which Eq. 1 was derived.
Masabuchi, Simmons, and M o n roe (Ref. 2) have produced a digital
c o m p u t e r p r o g r a m w h i c h in part
utilizes Tails' equation, (Eq. 1). The
applicable portion of the above c o m puter program was extracted and
slightly modified for use in this investigation.
The computer program utilizing a p p r o p r i a t e library s u b r o u t i n e s will
simultaneously graph the heating and
cooling curves for up to six points in
the total weld area and will calculate
the cooling rate at any two t e m p e r a tures for each cooling curve. In addition, a complete table of temperature
versus time data is computed and
tabulated along with the heat input in
kilojoules/inch.
Figure 1 shows a typical output
plot. The welding conditions used to
generate the thermal cycle shown in
Fig. 1 are identical to the welding c o n ditions used to make the test weld.
Note that the six curves represent the
weld centerline and five other positions, 0.03, 0.04, 0.05, 0.06, and 0.08
in. from the weld centerline. The three
last locations are in the HAZ. The
cooling rate has been calculated at
1300 F and 900 F for each of the
curves.* Also note that the thermal efficiency factor was considered to be
0.80 in this case.
Position of curves relative to
center line of weld
^ C e n t e r line
2800
- 0 . I I inch
- 0 . I 2 inch
- 0 . I 3 inch
2400
-0
Technique
The equation used to produce the
typical HAZ curves shown in Fig. 1
must be calibrated to the true thermal
cycle p r o d u c e d by the a u t o m a t i c
machine if the equation is to be useful. The proper efficiency factor was
'The 900 F cooling rate was considered to
be representative of the transformation
behavior of the steel during continuous
cooling (Rets. 3-6).
sling Rates,
F/sec
Center Line
I25.9
T(I300)
39.5
T( 900)
2000
0. I I
0.12
0.I3
11 8,4 2966.7 488.6
389
39.2
39.0
Gleeble sample
Hardness
1600
O.I4
II2.4
38.9
38 F/sec
Rc32
-I200
800 -
400
18
20
Fig. 3 — Typical thermal cycle exhibiting slow cooling rate at 900F
determined in the following manner.
A test weld was made using the
welding parameters shown in Fig. 1.
The test weld was cross sectioned
transversely at various locations. The
f u s i o n - H A Z interface was located
about 0.04 in. from the weld centerline and the m a x i m u m hardness zone
of Rc41 occurred at the 0.05 in. location.
A series of thermocycle curves that
correspond to the test welding conditions were computer generated by
varying only the efficiency factor,
namely at efficiencies of 0.70, 0.80,
0.90, 1.00, a n d 1.10. T h e p e a k
temperature of each curve that was
located at 0.04 in. from the centerline
was compared with 2750 F, the approximate melting point of steel; i.e.,
the temperature of the HAZ-fused
metal interface. The efficiency factor
that produced a curve that just
reached the melting point at the 0.04
in. location was 0.80, therefore this efficiency factor was selected for use. A
plot of the peak temperature of the
0.04 in. cycle as a function of arc efficiency is shown in Fig. 2.
Data
Calibration
Volts
27
Amps
384
Speed
= 60.00
Efficiency =
2.00
Kjoules/in =
20.7
Analysis
Based upon data from the 0.05 in.
location, thermocycle tabular print out
data, the HAZ metal at a point in time
2 sec (or 2 in., since the speed is 60
ipm) behind the main arc was 831 F.t
T h i s t e m p e r a t u r e is a b o v e t h e
t Note that the time scale on Figure 1 begins before the arc has passed a given
spot; therefore, 2 seconds elapsed time
occurs at about 3.5 sec on the graph's time
scale.
probable Ms temperature of 725 F. It
should be recognized that the above
statement strictly applies to the 0.05in. location; however, it is considered
to be valid for all locations in the HAZ
where the peak temperature was
above A, (about 1300 F). This c o n sideration was deduced by noting that
the 0.08 in. location thermocycle with
a peak temperature of 1407 F, or
about 100 F above A,, had a t e m perature of 790 F after 2 sec. Therefore, the curve with a peak
temperature of about 1300 F should
be above 750 F after 2 sec and certainly above 750 F at 1.5 sec elapsed
time. Therefore, the simulation indicates that it would be possible to
use an auxiliary heat source placed
1.5 to 2 in. behind the main w e l d ing arc to reheat the HAZ before it
reached the Ms.
Auxiliary H e a t i n g S i m u l a t i o n
Cycles
As deduced from the calibration
work previously described, the use of
an auxiliary heat source to decrease
the cooling rate appears feasible.
However, more simulation was needed to define the heat input of the auxiliary heat source so that the desired
c o o l i n g rate r e d u c t i o n c o u l d be
achieved. Although a wide variety of
auxiliary heating thermocycles could
be generated and a Gleeble test performed to evaluate each cycle, this
approach would have been too time
consuming. Therefore, a series of
thermocycles representing auxiliary
heat inputs in the range of 5 to 20
k J / i n . were generated. This was done
WELDING RESEARCH SUPPLEMENT!
413-s
360
H
340 —
320
300
M
280
260 —
o
CD
240 —
CD
220
o
or
200
c
o
o
u
I
O
O
cr>
qHr-H
180
160 —
H*
140 —
/
J
120
100
80 —
J
60 —
/
/
40
s
20
X
1
r\
1
1
0
1
1
1
1
20 25 30 35
Hardness, R c
1
40
1
45
1
50
55
Fig. 4 — 900F cooling rate versus hardness of Gleeble samples
by using typical weld parameters and
changing the efficiency factor to 0.501.00-1.50-2.00, respectively. Here, the
use of very high efficiency factors was
merely a convenient method for altering the t o t a l heat i n p u t w i t h a
minimum of key punching.
Figure 3 shows the 2.00 efficiency
factor (high heat input) t h e r m o cycles. In Fig. 3 the cooling curve at
the 0.05 in. location would have been
so close to the weld centerline that it
would have been indistinguishable
f r o m the c e n t e r l i n e c u r v e , even
though this location corresponded to
the zone of maximum hardness on the
actual test weld. This occurred because the theoretical equation using a
414-s I S E P T E M B E R
1 973
high efficiency factor depicted a much
wider weld than had been previously
simulated. This is analogous to the
physical situation; i.e., an increased
heat input would create a larger weld
pool. T h e r e f o r e , larger HAZ d i s tances f r o m the c e n t e r l i n e were
chosen to represent the desired HAZ
thermocycles; namely, thermocycles
located 0.11, 0.12, 0.13, and 0.14 in.
from the centerline.
The t h e r m o c y c l e of each plot,
which had a m a x i m u m temperature
closest to the 2400 F range, hence
analogous to the peak temperature of
the 0.05 thermocycle of that test weld,
was selected for Gleeble and subsequent hardness tests. This curve
would represent the heating and cooling cycle of metal located near the
HAZ-fusion interface when made at
high heat input conditions.
Gleeble samples were forced to undergo the various HAZ thermocycles
and their hardness levels were plotted
against the respective (900 F) cooling rates developed in the actual
Gleeble samples. The resulting plot is
shown in Fig. 4. The lowest hardness
level produced in this series was
Rc32. It was achieved with a cooling
rate of about 38 F/sec at 900 F and
with a heat input of 20.7 k J / i n . The
results of these runs indicate that the
desired auxiliary heating source must
be such that the cooling rate at 900 F
is below 38 F/sec. The heat input in
this case would be above 21 k J / i n .
In fact, an extrapolation of the data
of Fig. 4 (dashed lines) indicated that
a cooling rate of about 16F/sec would
be required to achieve the target
hardness level of about Rc25 or less.
Therefore, this value will be used as
first test criterion for any simulated
auxiliary heating thermocycle. This
test applies only if the auxiliary
heating cycle produced continuous
cooling; i.e., isothermal d e c o m p o s i tion was not considered at this time.
A new set of runs was made to
simulate the use of an auxiliary heat
source located b e h i n d the main
welding arc. Figure 5 shows a simulated auxiliary heat t h e r m o c y c l e
superimposed upon the first pass
thermocycle. The first peak was generated using the first pass weld
parameters with the calibrated efficiency factor of 0.80. The auxiliary
heat source thermocycle was g e n erated by using a second heat input of
10 k J / i n . The auxiliary heat source
was considered to have been applied
when the cooling curve at the 0.05 in.
location reached 800 F, which was
about 2.3 sec behind the first pass
electrode. Upon cooling after the auxiliary heat source had passed, the
cooling rate at 900 F was 57.6 F/sec.
From Fig. 4, this cooling rate would
be expected to produce a hardness of
about Rc35 which is above the Rc25
target value. The thermocycle shown
in Fig. 5 represented a total heat input
of about 17 kJ/in., which was approximately equal to the heat input
that would be developed if the first
and second passes were to be c o m bined.
Therefore, based on this cycle, and
assuming that the auxiliary heat was
representative of a second pass, it
was deduced that the hardness would
not be reduced to Rc25 or lower; i.e.,
the use of a multiple arc technique
while offering a substantial hardness
reduction would still not be enough.
Therefore, a series of simulated
auxiliary heat thermocycle curves
(0.05 in. position) were generated with
increasing heat input until the cooling rate at 900 F decreased to a value
below 20 F/sec. Figure 6 shows the
curve generated using a heat input of
25 kJ/in. for the auxiliary heat source.
The 900 F cooling rate was 16 F/sec
and from the extrapolation in Fig. 4
this cooling rate should be slow
enough to reduce the heat-affected
zone hardness below Rc25.
A Gleeble sample, arbitrarily designated A, was used to verify the
hardness reduction. The Gleeble cycle was slightly different from the actual curve in that the sample was
heated directly to about 2000 F and
held until reaching Point A in Fig. 6.
The Gleeble sample was then forced
to follow the computer generated
cooling curve. The altered cycle was
much easier to achieve in the Gleeble,
and t h e s a m p l e s h o u l d have
transformed in a manner equivalent
to a sample which had followed exactly the computer curve. The cooling
rate (at 900 F) of the Gleeble sample
was found to be about 13 F/sec and
the hardness was well below the Rc25
target value. This value is denoted by
an X on Fig. 4 and shows that the
original extrapolation was not quite
correct. Note that the X value is based
upon c o n v e r s i o n f r o m m i c r o hardness data and the Re hardness
scale ends at Rc20.
The thermocycle shown in Fig. 6
appears to have solved the problem,
but it has not; the simulated auxiliary
heat input is so great that, in practice, considerable melting would be
expected to occur. The heat input of
this auxiliary heat source would be
nearly 3Vz times as great as the heat
input used to make the weld's first
pass. An auxiliary heat source having
a heat input that high appears impractical, even if one were to consider that the extra energy could be
spread over a finite area rather than
an infinitesimal area as used in the 2D
heat flow equation.
Volts
Amps
Speed
Efficiency
Kjoules/in.
2800
2400
26
348
60.00
0.80
7.2
Cooling Rates,
F/sec
0.05
T(I300)
T( 9 0 0 )
2000
!=
=
=
=
=
I 78.3
57.6
TI - T2 spaci ng
T2 joules/in
Start' temp
Max temp
1600
= 2.30
» I0.0
= 800
= 2400
I200 -
800
400
Fig. 5 — Auxiliary
heating
thermal
cycle using a 10 kJ/in.
heat
input
Volts
Amps
Speed
Efficiency
Kjoules/in
2800
26
348
=
= 6000
0.80
=
7.2
=
Cooling Rates,
F/sec
0.0 5
48.1
T(I300)
T( 900)
Gleeble sarr pie
Hardness
T I - T 2 spacing
T2 joules/in.
Start temp
Max temp
I6.I
13 F/sec
Rc 4 0
= 2.30
= 25.0
= 800
= 2400
Diffusion-Controlled
Decomposition
Fortunately, the austenite in the
heat-affected zone can be made to
transform to relatively soft products
by transformation at essentially a constant temperature. Therefore, to study
this possibility two Gleeble samples
were run. The first Gleeble sample
was made to follow the original thermocycle shown in Fig. 6 except that
after reaching a temperature of about
1200 F on the second heating cycle
the Gleeble sample was held for 6 sec
and then cooled rapidly to room temperature.
The second Gleeble sample likewise was made to follow the thermocycle except that it was held at 1000 F
for 6 sec and rapidly cooled to room
4
Fig. 6 — Auxiliary
heating
thermal
5
T i m e , sec
6
cycle using a 25 kJ/in.
temperature. A cooling rate of about
500 F/sec at 900 F was achieved.
The hardness of the sample held at
1200 F was Rc35 and the hardness of
the sample held at 1000 F was about
Rc20. The hardness value of Rc20
thus indicated that a diffusioncontrolled transformation for 6 sec at
1000 F would be sufficient to reduce
the heat-affected zone hardness to
below Rc25.
heat
input
Summary of Predictions of
Simulation Studies
The analytical and Gleeble work
predicted that:
It would be possible to apply heat
1'/2 to 2 in. behind the arc to arrest
the cooling of the heat-affected
zone before this zone reached the
Ms temperature.
2. Multiple arc welding probably
W E L D I N G R E S E A R C H S U P P L E M E N T ! 415-s
would produce a hardness reduction to about the Rc35 level.
3. By maintaining a temperature of
1000 F for 6 sec the hardness of
the heat-affected zone could be
reduced to below Rc25.
4. A hold period of 6 sec at 1200 F
probably would not reduce the
heat-affected zone hardness u n less controlled slow cooling followed. Based upon these predictions, the welding equipment was
modified so that two welding arcs
could be used s i m u l t a n e o u s l y .
Preliminary results from a few test
welds made with the modified machine indicated that the hardness
of the HAZ ranged from Rc30 to
38, thus agreeing with the prediction.
Conclusions
A combined computer and Gleeble
s i m u l a t i o n t e c h n i q u e for w e l d i n g
applications has been developed. The
technique features (a) a Fortran IV
program to generate welding thermocycles and (b) a means of selecting the proper arc efficiency factor,
and (c) a means for verifying the
metallurgical effects upon the welded
material by utilizing the Gleeble.
This technique permits the simulation of welding processes to accurately predict the effects of process
changes upon metallurgical properties of the weldment due to the thermocycles imposed by the welding
process.
References
1. Tall, Lambert, "The Strength of
Welded Built-up Columns" Dissertation
Lehigh University, Ph.D., 1961, part 2, p.
12-18.
2. Masabuchi, K.. Simmons, F. B., Monroe, R. E., "Analysis of Thermal Stresses
THE WELDING
ENVIRONMENT
I
and Metal Movement During Welding,"
Redstone Scientific Information Center —
820.
3. Inagaki, Michio and Sekiguchi, Harujiro. "Continuous Cooling Transformation
Diagrams of Steels for Welding and Their
Applications," English Translation —
Transactions of National Research Institute (Japan) for Metals, Vol. 2, No. 2 (1960)
p. 102-125.
4. Jhaveri, P., Moffatt, P., and Adams,
C, "The Effect of Plate Thickness and
Radiation on Heat Flow in Welding and
Cutting." Welding Journal, Research
Suppl., Vol. 41 (1) 125-16s (1962).
5. Dorschu, K. E., "Control of Cooling
Rates in Steel Weld Metal," Welding Journal, Research Suppl., Volume 47 (2) 49s62s (1968).
6. Hess, W. F., Merrill, L. L. Nippes, E. F.,
and Bunk, A. P., "The Measurement of
Cooling Rates Associated with Arc Welding and their Applications to the Selection
of Optimum Welding Conditions," Welding Journal, Research Suppl., Vol 22 (9)
377s - 422s (1943).
A research report on
fumes and gases generated
during welding
operations
The Welding Environment presents important new data on the fumes produced during welding and recommends standard methods for sampling and analyzing these
fumes.
Based on a study of welding fumes conducted by Battelle Memorial Institute, the
report is divided into three major parts. The first of these is essentially a state-of-the-art
review which gives the essential findings in the literature surveyed with an interpretation of the results and their implications.
A lack of uniformity in sampling and reporting data observed in Part I led to the experimental investigation reported in Part II. Part IIA reports on the development of uniform
procedures for generation, sampling, and analysis of welding fumes and gases and includes many tables of data on compositions of welding fumes using several different
filler metals and fluxes. Part MB reports results of a supplemental investigation. Part III
suggests uniform methods for sampling and analysis of welding fumes and gases.
The Welding Environment contains 124 tables, 40 illustrations, and extensive literature references. Six appendices at the end of the report present supplementary information on Part 1 plus a discussion of federal and state safety regulations and a glossary
of medical terms.
CONTENTS
Part I: Review of the Literature on Welding Fumes and Gases. Introduction. Hygienic Considerations of Welding Fumes and Gases. Weiding Fume and Gas Investigations. Other
Fume and Gas Investigations. Ventilation Considerations. Discussion of Prior Investigations. References-Part I. Part IIA: Experimental Study of Arc-Welding Fumes and Gases.
Introduction. Background. Materials. Equipment. Procedures. Evaluation of Analytical
Techniques. Total Fume Studies. Fume Measurements in the Helmet Region. Effect of
Welding Position on Fume Concentrations. Part MB: Supplementary Investigation of ArcWelding Fumes and Gases. Introduction. Experimental Studies. References—Part II.Part
III: Proposed Procedures for Sampling and Analysis of Welding Fumes and Gases. Introduction.
Scope. Procedures. Appendix A: Physiological Effects from Exposure to Welding Fumes.
Appendix B: Aerosol Deposition and Measurement. Appendix C: Air Sampling and
Contaminants. Appendix D: Fume Analysis Techniques. Appendix E: Federal and State
Regulations. Appendix F: Glossary of Medical Terms. 792 pp., 8V2 in. x 11 in.,,
paperbound.
The list price of The Welding Environment is $20.00.* Send your orders for copies to
the American Welding Society, 2501 N.W. 7th Street, Miami, Florida 33125.
"Discount 25% fo A and B members; 20% to bookstores, public libraries, and schools; 15% to C
and D members. Add 4% sales tax in Florida.
416-s I S E P T E M B E R
1 973