Materials Chemistry and Physics,19 (1988)447-461
EVALUATION
OF
RESISTANCE
INTERGRANULAR
A.
KARAS,
FOLD1 V.
447
OF STAINLESS
STABILIZED
STEEtS
TO
CORROSION
CfHAL
and
V.
[
27.2
62,
V.
SONP,
VANEK (C.S.S.R.)
CfHAL
State
Research
Praha
9,
Institute
Bechovice
of
190
11
the
Protection
of
Materials,
(C.S.S.R.)
Received September 7, 1987; accepted October 14, 1987
ABSTRACT Relationships and
the
between
parameter
of
susceptibility relying
of
on
the
CrNi
their
applicability
culary
ateels,
suited can
integrity
to
of
discussed
in
stabilized
use
at
the
to
modify
the
not steel
the
final
as
Obviously,
the
In
that
the
case
normal
appears value
the
of
including
the the
stabilization
0254-0584/88/$3.50
accurate data
coefficient
in
the
is
to parti-
since
trimming before
the
continuity
steelmaking by
would
evaluation
of
high.
effect
relation
auste-
composition
products test
indicating
treatment
surprisingly
in method
Furthermore, of
the
low-carbon
steelmaking,
II.
this
efficiency
solution
paper The
assess
corrosion to
chemical
final
to
contents
and
making
be
the
carried
the
test out
on
prescribed.
most
includes
this
disturbed
into
corrosion;
carbon
derived
applied
of
the
parameter be
intergranular product
stage
and
intergranular
steels.
made to
were
to and
be
the
that
analysis,
for
calculation
k
chromium
steels
for
would
processing
resistance
were
referring
teeming, and
effective
stainless
chemical
nitic
additions
the
On of
of
contrast
the
degree
of
obtained
if
chemical
analysis.
stabilization
and
sensitizing
at
the
other
the
efficiency
nitrogen to
is
complete
the
is
hand, for
significant
other
tramp
the
the
for
650°C/l
h/air
relatively
calculation for element-
lower without
the
degree the
of
sulphur,
0 Elsevier Sequoia/Printed in The Netherlands
448
INTRODUCTION Stainless and
such
steels
with.which
hazard
several and
power
not
of
only
in
contents
carbon
and
corrosive
balanced
loads to
corrosion
factory,
or
if
structurally changes
ments
are
can
be
chemical is
their
also
take
with
guaranteeing to
the
chemical
the
CrNi
Eauations
at
of
of
satisin
that
hardly
These
require-
steelmaking methods
which to
The
make
modify
present
procedures
the
paper
proposed
corrosion
with
stainless
a
of
chemical
is
incidence
paramet.er
a
resistance
of
on
for
reference
austenitic
the
steels,
[1,21.
point
and
stepwise
complemented
elements
in
alloying
susceptibility
specially to
intergranular
low-carbon the and
resistance
Taking
as the
with
of
type and
limit
on
to
/i/ of
the
the
Crl8Ni.10
determined
and
chromium
from
/ii/
the
inter-
chromium
basis
effects
molybdenum, corrosion
a
of
contents
the
steels and
both
indicating
contents
between
stainless nickel
corrosion
corrosion,
effective
dependence
Cr17Ni12Mo2,
of
equations
sufficient
proven
carbon,
interaranular
intergranular
indicating with
to
composition
based
starting
of
so
stage.
stabilized
re-
are
measures
the
me-
their
those
suitable
intergranular
empirically
of
of
severe
drawings.
only
inspection
one
stabilized
that
grades
and
not
steelmaking
to
analysis
corrosion, as
proven
design
of
which
with
of
heavy-duty
properties
corrective
the
use
and
provided
with
contents
in
identical
appropriate
the
steels
conditions
carbon
using
on-the-spot
specification
granular
the
by
determinina
stabilized
of
and
modified
type.
for
The
are
elements
steels
reduced
in
only
mechanical
in
resistance
of
value
and
composition
concerned
and
them
properties
possibly
low-carbon
applications
to
tramp
stabilized
application
on
needed
to
find
mi-
in
given
and
with
in
established
but
possible
in
The
can
and
satisfied
technologies, it
types,
also
and
engineering
therefore
CrNi
corrosion
required
chemical
is
steels
and
guaranteed
alloying
imposed
their well
in
composition
are
in
of
composition. steels
are
sistance
or
is
incurred,
attention
but
carbon,
environments
chanical
is
content
nitrogen,
stainless
service
especially
low-carbon
and of
a
austenitic
chemical properties
failure
balanced
austenitic
normal
any
and
Maximum
suitably
molybdenum
optimized
in
industry,
engineering. a
with
reliability
damage
branches
seeking
with
of
alloys
physico-metallurgical
mechanical,
resistance nimal
and
rest and
the by
degree the
449
corresponding ship
k
was
=
-
this
resistance
the
100,
content reliably k =
k
Cr.
=
Cr
+
c*
=
C +
The
coefficient
1.0
and
kl
is
CrNi
of
The
of
in
may
be
the
the
parameter
equal
to
inter-granular
to
in
the
in a value
when
of
appear
addition
corrosion,
has
data,
is
mild may
factors
niobium, d,
value
silicon,
16; attack
steels
having
effect
of
decisive
for
and
include
they
the
degree grain
relationships chromium
and
are carbon
satisfied (in
wt.
for %),
the
respectively:
(2) (3)
in
eqn.
molybdenum
in
taken,
with and
and
is
(2)
for
CrNiMo
on
to
the
the
this
288OC
[ill
oxygen
at
100
H2S04, h/air
110
the to
1.7
with
the of
be
equal
passivating
was
used
ranging The
value
test
in
2.2 the
current in for
a
Cu;
a
sensibilization
this
standard of
(see
Fig.
effect
of
density
solution
water
. g CuS04.5H20,
between of
evaluations
to to
measurements value
values
results
referring
critical
111;
up
conditions.
steels,
than
take
comparison
potentiokinetic
% KSCN
may
different
reference
lower
polarization
ml
and
thermodynamic
factors
effective and/or
constant
resistance,
16,
the
of
etc.
general
[l,g,lO]
and
650°C/1
% [7,8].
intergranular
b
1.7
value
x)
0.05
is
nickel
titanium the
chromium,
(Ni-kZ)
The
of
the
C*
of
of
improvement
b MO
coefficient
0.01
with
and
the
and
[4-6]
other
14
contents
solution
relation-
corrosion.
content
effect
occurrence of
deformation,
following
to
these
to
cold
effective
+
limited
between
the
sufficient
composition;
The
carbon
around
the
sensitivity
size,
general
(:
on
elements,
harmony
Effects
of
chemical
a
intergranular
effective
corrosion, by
ensures
14,
to
molybdenum
According
is
tolerated. value
the
of
stabilizing
in
carbon
is
modified
steels.
k
of
Cr.
intergranular
and
that
‘I,
parameter
resistance
effect
carbon
stabilized
a
the
the
to of
to
the
I31
(1)
also
nitrogen
solution
indicating
relationship
content
is
for
indicates
including
when
standard
&C‘
value
equal
in
derived
Cr.
whose In
test
containing
lowI).
chromium in
of
H2S04 36
+ ppm
0
lCL473BC
13<
ICL167 CN EL 167F
$ + traces m*
susceptible
C’I%l
-
1. Results of testing steel grades ICL 473 BC sentitized at Fig. 7OOoC/30 min/5OoC/h and steel gradfs ICL 167 CN and ICL 167 F with optimized chemical sensitized at 725oC/30 min/50°C. h for resistince to intergranular corrosion composition (see below), in standard solution (10 % H SO + 10 % CuSO . 5 H 0, 70 h, plottins: dependence of4the ef?ective content boiling) ; bend test; of chromium on the effective content of carbon (in wt. %) according to the equations with coefficient b = 1.2. The lines for the parameter k demarcate the incidence of low-intensity intergranular corrosio’;;. The parameter below which the steel is not safe against intergranular corrosion is equal to 25.7 according to the set of melts investigated. chemical
grade Creusot-Loire
C
ICL 473 BC ICL
0.04
167 CN
ICL 167 F
Mn
Si
1.0
2.0
analysis,
% by
weight
Cr
Ni
MO
18.5 20.0
9.0 10.0
/0.15/
N
B
0.08
-
max.
0.045
1.0
2.0
17.0 18.2
11.5 12.5
2.3 2.8
0.08 max.
0.03
0.5
1.6 2.0
17.0 18.0
12.0 12.5
2.3 2.7
0.06 0.08
0.015 0.0035
Bearing in mind the statistical nature of the testing [5, 121 done to validate the constants k, and k2 in eqn. (31, the value of kl will be 0.002; for chromium of
carbon
content
is
the
following
= C + 0.002
(Ni-3.0)
a about
constant 19
%,
relationship
k2 so
it
will
that is
for used
be
around
the
for
effective
20
when
the
content
non-stabilized
steels: c.
(4)
451 The
value
melts
of
of
treatment 1
than
h/air;
to
the
see
141, a
tionship
1.
of
that
and
contents
to
the
is
of
on
the
of
a
Ti
in
where
Ti
tanium
content
can
the
is
the
titanium
solid
solution. be of
fairly
stable
since
do
differ
not
carbides
at
sulphur
in
Using bound
TiTiN
where
to
steel
nitrogen
3.43
N
is
of
in
bound
extent the
of
high
titanium)
niobium.
the
Relying
total in
content
this
to
carbon,
a
parti-
manner. bound
nitrogen
nitrides
dissolve
to
be
to
indicate
bound
to in
much
Roughly
a
to
S tg
is 7 total
is
free
of
is
Ti2S
content
steels
readily the
ti-
niobium
nitrogen
less
the
nitro-
stabilized
half
the
the
Ti
the
similar
TiTi
bound
and of
element
and
of
steel,
titanium
distribution
of
means
of
the
stabili-
what
excess
titanium
contents
by
niobium
(5)
the
rated
or
follows:
the
temperatures. is
staand
exceeding
titanium
is
in
relationship
in
of
16.2.
rela-
carbon
to
of
i.e.
TiTiN
stabilizing
much, higher
the
=
a
carbon
to
+ Tir
The
indicated
content
the
degree
that
distribution
limited
into
Furthermore,
to
content
sulphur,
the
(i.e.
as
is
titanium
deciding
titanium
steel,
+ TiTiC
total
as
for
expressed
to
could
The
be
of
111,13,
15.7
both
heat
650°C/
=
contents
contrast
the in
bound
TiTiC in
in
of
bind
ratio
to
k
included
their
at
steels
content
mass
of
demanding
these
perfection.
with
el.ement
more
niobium
(or
industrial
conditions
parameter
be
referred
media,
+ TiTiN
is
titanium
or
reliable
knowledge,
instance,
= TiTi2S
gen,
some
in of
effective
approaches
present
zone
inspecting
sensitizing
rather
values
the
by
stricter
normal
shall
also
completely
stabilizing
cular
the
content
stabilization
adverse
thus
elements,
stabilization
degree
the
the
ratio, not
to
titanium
carbon
to
is
stabilization
other
stoichiometric is
to
Since
the
determined
apply
transition
indicates
steels.
zation)
The
pertaining
nitrogen
k,
steels,
corresponds
effect
bilized
parameter
sensitization
Fig.
range
The
the
low-carbon
than
content
[15,16]. of
titanium
I171
(N-0.001)
the
content
of
(6)
of
nitrogen
(in
wt.
%)
then,
for
titanium
452
bound
to
TiTiC
=
and
carbon,
Ti
-
we
1.5
thence,
=
f
where the
f”,
the
and
upon
of
nitrogen
is
The
not not
and
for
be
equal
C.
=
heating
paper
is
S
concerned
efficiency; content
determining
the
with
of
only
of
content
the
content
of
of
sulphur
in
finding
out
the
are
necessary
for
Ti-stabilized
k
-
the
the
of
wt.%.
values
carbon
of
for
resistance
to
stabilization-annealed would
that
parameter
k,
relationships
non-stabilized
steels;
for
the
values
of
the
carbon
will
values
contents
coefficient
chemical
of be
roughly
never
of
-
CTiC
C. = C + 0.002
(Ni_10)
_
f
Data
are
lacking
and
other
still
elements,
on and
unequivocally
the
of
the
occurs
will
of
the
effective
these bound
efficiency,
expressed,
composition
(Ni-10)
included
compo-
the
values
in
the
C +
if
if
efficiency
phenomenon
content
chemical
f
in-
content
parameter
is
coefficients
0.002
be
the
these
effective
a
f”
is
TiC
titanium
of with
including
carbide
and
compared
coefficient
It
of
period
and
of
(8)
efficiency,
incompleteness f*
-
of
dissociation
the
content the
the
the
and
unity
(N-0.001)
coefficients
determine
respective
of
S-3.43
approach, in
a metal
treatment.
derived
the
Ti-1.5
of
either);
to,
(7)
carbon,
to
contain
Tir
bound
order
carbon been
the
known,
the
solution In
are
corrosion.
that
f
-
4
known
the
intergranular
after
f
of
calculating
or
S =
(coefficient
present
steels
of
and/or
coefficient
grades
content
temperature,
steel is
sulphur
(N-0.001)
understanding
solution,
sition
3.43
4
f‘
solid
write
f*Ti-1.5
of
dependence
the
-
-;;_ =
lack
in
S
for
NaTi CTiC
can
be
used
depending as
of
that
had
relationships carbon
so
steel,
content
will
together
that
the
upon
with
effective the
knowledge
follows:
(9)
Ti
-
the
1.5
effect changes
into
the
S 4
of in
3.43
(N-O-01)_
manganese, their
relationships
(10)
silicon,
contents
can
discussed
boron hardly in
the
453
foregoing.
However,
negligible
within
stabilized
austenitic
steels
with
effect
of
of
tests
used the
to
nular
the
corrosion
present stabilized
-
steels
chromium to
obtain
or
f”
and
are
not
silicon,
be in
Ti-
apply
where
the
of
the
to
the
melts
in
possibility
mind
for
k
-
the
18
were to
the
of
sus-
intergra-
subject to
the
values,
[3]
Ti-stabi-
the
between
of
standard
corrosion
resistance
of
the
of
stainless
Having
parameter
determinant
of
these
for
ranges
and
intergranular
relationships
or
occur
does
analyses
grades
Out
I).
and
will
titanium
to
four
test
Table
using
or
chemical
assessment
values,
which
of
steels.
carbon,
the
with of
standard
the
normally this
manganese
resistance
(see
paper
they
effect
ignored.
melts
CrNi
after
their
Still,
stabilized
232
that
which
of
be
indicate
austenitic
ceptible
in
accumulated
of
assumed
steels.
contents
steels
basis
lized
limits
cannot
were
be
CrNi
higher
Results
may
the
these
Evaluation
on
it
of
contents
prime
of
concern
was
coefficients
efficiency
of
the
evaluate
f,
the
f‘
degree
of
stabilization. First,
effective
melts,
and
tationally basis
of
were
rosion
for
f
these.
parison
the
of
lected all
fairly
Table
included
I);
those
in
further
Effective
content
melts,
ferent
values
and
to
a
the
accuracy
amitted. susceptible
obtained,
intergranular
melts
degree of
A
were
corThis
to
calculations
86
of melts
values
coeffiwere
intergranular since
the
high
stabilization
values of
com-
of
with
of
the
total
the
indicating
calculations f:
high
on
attack.
further
the
calculated
14-16,
corrosive
all orien-
which
=
efficiency
with
of
of
the
0.5
sulphur,
were
included.
comparison values
to
of of
5
was was
coefficient
from
limit
carbon
parameter
starting
A
k
for
calculated
se-
corrosion
their
number
was
small.
lected
its
of
for
of
were
then
parameter
this
point
calculated was
susceptible to
to
efficiency,
was
carbon & was
this
steels
those
i.e.
of
values
resistant
contribute
(see
were
of
limit
starting
k,
cannot
cients
values the
coefficients
parameter
that
chromium
parameter
between
the
of content
unity;
The
steels
was of
=
with
points and
values of
effective
compared
breaking
content
the
unity;
the the
then also
of the
calculated resistance
calculated
efficiency
content
values
for
calculated
of
of
pertaining
for f
both
at
the the
.lO
nitrogen
rhe
parameter to
individual
sedif-
steps and
k
with
08Crl8NilOTi
0.08
1.5
2.0
0.10
09Crl8NilOTi
417248
2.0
0.12
lCrl8NilOTi
Mn max.
number
C max.
the
austenitic
2.0
417246
&N
and
of
0.12
lCrl8Ni9Ti
types)
Specification
grade
321
(AISI
type
I.
Table
0.8
1.0
0.8
1.0
.
;;‘;
.
17.0 lg . o
17.0 19.0
;;‘;
Cr
investigated
Si max.
of
stainless
.
;;‘;
1;‘:
.
.
9.0 11.0
l;‘;
Ni
of
5.C/O.6
5.C
5.C/O.8
5(C-0.03)
0.035
0.045
0.035
0.045
P max.
these
stabilized
Ti min/max
heats
steels
0.012
0.030
0.020
0.03
S max.
steels
with
78
14
50
90
total
titanium
%)
18
9
23
26
number of selected
(wt.
1
5
4
8
melts susceptible
455
09Crl8NilOTi lCrl8NilOTi lGrl8NI
l
9Ti
08Crl8NilOTi susceptible 4.
+ A
0
+e
c
*A+:;;
t
l
+A A
l
A A
.
+ ++
A
A: l
+ A
l l
0
0.04
-
0.08
0.04
___)
c' [%I
Results of testing resistance of stabilized steels to Fig. 2. intergranular corrosion (selected melts) after testing according to CSN 03 8169 in standard solution for the value of the coefficient of efficiency of the degree of stabilization f = 0.98 and constant b = 1.2, plotted to show the dependence of the effective content of chromium on the effective content of carbon with reference to the transition zone for the incidence of susceptibility to intergranular corrosion with k = 14-16 coefficients the
known
of
The
comparison
ing
point
Fig.
2).
the
line
terms
of
dependences (see
two
melts,
granular limit
of with
f
=
lies To
the
effective
the
for Fig.
the 3).
of of
value
in (steel
of
the
k =
the of
14.
of
of
test
of the
the break(see
out
from
corrosion of
f
=
of
0.96; f
for
resistance
to come
in
chromium
presented
coefficient
type)
calculated,
where
the
lCrl8NilOTi
comple-
values
stand
content
efficiency
is
corrosion
melts
are
(IO)
0.96;
thus
intergranular
sections
of
carbon
optimal
some
a
0.94;
intergranular
effective
value
0.92;
position
to
carbon,
the
satisfactory corrosion
to degree
coefficients As
the
resistance
dependence content
give
to
eqn.
composition
Therefore, =
content
resistance what
f
(,
to
chemical
unity.
values
relation
to
according
the
and
for
parameter in
demarcates
the
0.9
made
the
that,
where
between
0.98 for
that
showed
was
illustrate
effective
0.92
the
lay
values
coefficient
f,
coefficient,
calculation
0.98.
the
efficiency
this
completely,
mentary
on
of
value
on these
0.94;
decreases, interdown
below
456
+ lCrl8NiSTi
$ 19 . 6
I 18
17
0
0.02
0.04 0
Fig. 3. Comparison of transition zone; three ciency f are shbwn.
0
0.02
a04
results lower
0
oQ2 from values
0.02
aD4 Fig. of
0
oD2 -
2 in the vicinity the coefficient of
a04
0
O-02 -
Fig. 4. Comparison of results from Fig. of efficiency f‘ in the vicinity of 0.7; is not included.
0.04 C' [O/o]
3 for three the effect
of the effi-
004
c’ [Vol coefficients of nitrogen
The
calculations
plotter. on
the
chemical
contents
of
nitrogen
of
efficiency
content
of
(coefficient and
inc;luded.
mutual parameter of
In
2
will
efficiency
and
is
f‘
not
show
that
0.7
the
the
(see
optimal
Fig.
chemical
For
analysis both
the
f”)
are
calculations
having
value
4).
coef-
which
efficiency
the
melts
the in
where
of
HP 9862A data
sulphur,
instances
both
heats
and
include
instances
in
for
instance
selected
the
indicated
9810A
always even
for
or
HP
not
(coefficient
former
of
=
do
sometimes
f‘),
contents
the
comparison
computer
calculated
efficiency
sulphur
using
analyses
was
nitrogen
of
nitrogen not
made
the
ficient the
were
Since
of
the
and
limit
a
values
the
of
coefficient
value
of
f”
=
0.72
one of the unsatisfactory melts closely approaches the value of parameter E = 16, although none of the satisfactory melts is below the limit for the parameter k = 14. In the latter instance the value of the coefficient f" ficiency for
of
the
stabilization
resistance
mical
The
and
in
it
and
the
the
stabilizing
These
to
only
steels.
Since
lected
values
of
stabilization carbon
will
doubtedly
be
Neglecting content
for of
the of
be
used,
added
the
effect
chromium
che-
The
both
is
given
molybdenum
produces
an
obtained
much in
essential
the
of
steels
the
with
the
degree
will
val.ue
seof of
be
MO-modified
effect
manners,
stabilized
content
attention
of
directly.
complete, of
and
required.
quantity
also
effective
knowledge
Nb-stabilized
latter of
the
or
not
efficiency
the
will
quickly
a variety
but is
where
calculated
in steels
composition
steels this
available or
be
the
austenitic
soon,
must
re-
in
teeming;
made
[7,8,11-141,
where
metal
composition
modified
the
susceptibility
the
be
low-carbon
reduced
to
inducing
before
very
coefficient be
and
complete
composition
stabilized
must
to
chemical the
the
chemical
be
calculated.
useful
evaluation
the
stainless
will
their
ef-
possibility
calculated
chemical
conditions
composition
the
a
referring
the of
calculated
can
chemical
be
heat-affecting
analysis
element
not
on
enable
trim
be
relationships
assess
by
chemical k
to
studies
based
zone,
parameter
optimized
these
industrial
realistic
offers
although
principles
in
the
steels
are
corrosion
assessed
0.66
known,
that
temperature
be
to
exactly,
physico-metallurgical
Obviously,
The
not
obtained above,
intergranular
make
to
is
results
critical to
austenitic
no-t. quite
composition
lationships
to
of
though
evaluated,
is lower (see Fig. 5). The
equal
f”
un-
grades. at
present.
of
the
affective
on
the
final
the
458
a OBCrl8NilOTi
i
18
0.02
Fig. 5. Comparison of the effects of neither
of
more than or
the
content
of
less
original tuated of
steel
steels
are
these
equations
and carbon.
a tramp element. the
Obviously, calculation the
case
normal
the is the
the
significant
other
efficiency
On the of for
tramp element parameter
other
of the
5 does
of
their
of
hand, f‘
nitrogen degree
- the not
these
of
sulphur. greatly
the
= 0.7 is
of
types
kept
fluc-
being
somewhat
the
of close
if
chemical
composition.
of
the
steels
for - 1050°C/
- appears
relatively
Omitting
contents
effect
obtained
the
lower calculation
an indication
reduce
to the
contents
stabilization
h/air
stabilization
on
in a quantity is
for
contents
effective
include
complete
f”;
detrimental.
form the
degree
of
furthermore,
authors
evaluation the
nickel
nickel
indicate
at 650°C/1
efficiency
effect
the
when present
of
treatment
of
equally
the
indicating
and sensitizing
high.
coefficient
including
data
solution
30 min/water prisingly
the
beneficial
most accurate
includes
is
The calculations
which
In that
is
spite well
to
for
0.02 0.04 C’ [%I
-
depends,
[II,
in which
molybdenum, that
effects
concerned,
equations
8 and 12 %; in
between
chromium
different
than 10 %, which in
empirical
complicated,
the
chromium
Where stabilized
"0
results from Fig. 3 for three values nitrogen nor sulphur are included.
I201 . Neglecting
result
0.02
-0
0.04
of in
of
without
how nitrogen
contrast
sulphur
the value
survalue
to
the
in calculating of
the
coef-
459
ficient
of
efficiency,
negligible, =
as
although
is
documented
the
effect
the
fact
basis
of
by
of
sulphur
that
the
is
not
value
of
f”
=
0.66. The
results
equations made
obtained
were
according
However,
to
this
sistance
to
tents
of
on
the
orientationally
compared
equation
equation
based
is
not
intergranular
titanium
on
apt
a
to
corrosion
and
other
the
above
empirical
with
the
calculations
statistical
analysis
reliably where
elements
is
indicate the
range
of
1211. the
re-
the
con-
wide.
CONCLUSION Relationships
between
carbon
and
the
assess
the
susceptibility
corrosion
relying
carbon
austenitic
relation
to
The
of
bound
content
of
carbon.
(or
f‘,
a
f”, of
study
from
of
according and of
as
232
the
to
melts
the
in
the
of
nitrogen
CSN
the
to
neither value
The results
of
range
content the
not of
0.7
types
their
the
to
is
to
of
of
to
the
of
chemical
nitrogen
coefficient
of
re-
Where
the
calculation,
the
CSN
quoted).
and
is
the
completbasis 18
its
value
the
is
of
in
sulphur even
content into
study
as
of
are
employed
under
that
is
stipulated
included
composition
value
coefficient
was
steels
melts
sulphur
coefficient value
of
corrosion
If
not
f
the
this
conditions
efficiency
the
the
both
unity: of
the
nor
of
steels;
test.
This
stabilized
these
intergranular
efficiency
of
on
for
known
level.
in
stabilization
stabilized
values
valid
value
upon
depends constructed
approaches
according
the
reference
is
steel
decreases individual
the
0.98
low-
paper
effective
that
in
stepped
terms
the of
standard
efficiency
of
coefficients
grades
included
to
this
in
value
susceptible
8169
for
test
in
compare
-
applied
steels;
indicated
were
be
are
value
calculation,
below
03
results
standard
bilization
be
four
to
of
the (the
may
of
found
coefficient
assessed
If
case
composition),
to
steels.
total
efficiency
contents
after
the
the
were
nitrogen
0.98
The
the
and
derived intergranular
in
stabilized
was
in
and
discussed
to
chromium
were to
analysis,
these
stabilization
of
that
steels
were
for
carbon
chemical
these
chemical
applicability
of
&
stainless
steels,
validated
content
eness
the
contents
resistance
of
on
were degree
effective
of
CrNi
their
lationships
the
parameter
lower,
stato
with
standards. are
known, i.e.
0.7. following obtained:
recommendations the
procedure
can
be
made
discussed
in
with the
regard present
to
the
paper
concerning
the
evaluation
intergranular suited
corrosion
for
ditions
use
can
at
be
made
nuity
and
integrity
into
final
for the
to
of
the
the
k.
trimming
composition
and
not
be
the
test
ad-
before the
conti-
processing
of
disturbed
this
to
particularly
Furthermore,
steelmaking would
as
is
steels
since
chemical
corrosion;
product
and
parameter
products
stabilized
steelmaking,
modify
of
of
practicable,
the
intergranular final
resistance
stage
to
steel test
is
the
referring
teeming,
on
of
by
would
making
be
the
the
carried
out
prescribed.
REFERENCES
1
V.
Eihal,
SNTL
Intergranular
Praha,
2
V.
3
ESN
krystafove
korozi,
4
J.
Bleton,
I<.
-48
(1951)
525.
V.
Cihal,
Sbornik
5
Eihal,
6
H.
7
R.F.
Basic
Mai 9
P.L.
on
10
the
v
Ostrave,
Nov.
1969.
-35
(1964)
and
M&m.
-11
(1965),
Sci.,
5,
247.
Countermeasures
Solomon
Variabilities
Electric
k mezi-
of 1980,
Pipe
Electric
6.
H.D.
in
oceli
Rev.Metall.,
California,
I paper
Phenomena General
in
Alto,
Adressen,
Studies
1981,
Palo
Inst.
Sensitization
VSB
953,
Seminar
Alloys,
1967.
Bastien,
Eisenhiittenw.,
BWR’s,
and
643.
revid.vydani
P.
No
Steels
korozivzdornQch
praci
DRU
Proc.
Research Fox,
(1985)
II.
and
ved.
Arch.
in
40
1962,
of (1984).
odolnosti
Blanot,
Fullman,
M.D.
listy,
CAFL,
Zitter,
Power
Amsterdam
ZkouSeni
Rapport
Cracking
8
Hutnicke
038169,
817;
Corrosion
ELSEVIER
of
Stainless
and
D.F.
Fabrication Steels,
Comp.,
Gobin,
Corrosion
Anticorrosion,
2
V.
Eihal,
Corrosion-Traitments-Protection-Finition*
related EPRI
Schenectady,
F.
Taylor,
NP
-
1823,
N.Y.
(1961)
119. -18
(1970)
441. 11
P.
12
F.
Combrade
et
al.,
Materiaux
et
Techniques,
Sept.
-Oct.
1977,
561. Leroy,
J.
interqranulaire
de
Creusot-Loire, 13
P.
Rabbe,
tallurgie
Freycenon
DRU C.
Amzallag
de
Saclay,
and
1.acier No
285, and June
J.
Heritier,
inoxydable July 3.P. 1974.
Tenue I.C.L.
& la
corrosion
167CN,
Rapport
1977. Raoul,
17’
Colloque
de
M6-
463.
14
15
P.
Rabbe
and
J.
(eds.),
Ppedn.
Related
Alloys,
delphia.
Pa.,
V.
Masaiik
Heritier na
in
ASTM
Commitee
Atlanta, 1979,
and
V,
C.R.
Brinkman
and
Al
Steel,
Nov.
1977;
Proc.
Werkstoffe
u.
Corrosion,
J.
I
Ga.,
H.W.
Garsin
Stainless
and
ASTM
Phila-
134. Cihal,
-25
(1974)
330. 16
V.
17
korrozija
giz.,
la
E.
Cihal
and
Pitter,
materialy,
12
712. Chimu5i.n
F.F. i
V.
Masapik,
(1974)
and metallov
1960,
Z.F.
Istrina, v
Meikristallitnaja
naprjaienom
sostojanii,
korrozija Moskva,
Mas-
45.
PSibil,
V.
Cihal
and
F.
Poboril,
Strojirenstvi,
-34
(1984)
300.
19
V.
20
R.A.
21
A.G.
Cihal,
Hutnicke
listy,
E.L.
Mulford,
Hall
J5_ (1980) and
C.L.
703. Briant,
Corrosion,
-39
(1983)
132.
8
I
(1984)
G.A. 25.
Burjakovskij
and
M.A.
Solodovnik,
Metallurg,