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Summary
To improve pitting and crevice corrosion resistance in
aggressive environments, SX 317L is alloyed with
between 3.0 and 4.0%, molybdenum. To counteract
the ferrite-forming tendency of molybdenum, more
nickel must be added, which results in improved
general corrosion resistance. It has excellent
formability and fabricability.
SX 317L is not prone to intergranular corrosion in the
heat affected zone after welding.
Typical
Applications
Applications for SX 317L are generally in process
equipment in the pulp and paper, fertilizer and
chemical industries. In the pharmaceutical
industry, SX 317L is sometimes recommended because of
the necessity to avoid metallic contamination.
Chemical
Composition (SATM A240)
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SX
|
C
|
Mn
|
P
|
S
|
Si
|
Cr
|
Ni
|
Mo
|
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317L
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0.03
max
|
2.00
max
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0.045
max
|
0.030
max
|
1.00
max
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18.0
-
20.0
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11.0
-
15.0
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3.0
-
4.0
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Typical
Properties in the Annealed Condition
The properties quoted in this publication are typical
of mill production and unless indicated should not be
regarded as guaranteed minimum values for
specification purposes.
1.
Mechanical Properties at Room Temperature
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Typical
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Mn
|
|
Tensile
Strength
MPa
|
570
|
515
|
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Proof
Stress (0.2%
Offset)
MPa
|
330
|
205
|
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Elongation
(Percent in 50 mm)
|
50
|
40
|
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Hardness
(Brinell)
|
165
|
-
|
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Endurance
(fatigue)
Limit
MPa
|
260
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-
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2.
Corrosion Resistance
As a rough guide the following examples are given for
pure acid/water mixtures.
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Temperature
o C
|
20
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80
|
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Concentration
- % by mass
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10
20
40
60
80 100
|
10
20
40
60
80 100
|
|
Sulphuric
Acid
Nitric Acid
Phosphoric Acid
Formic Acid
|
2
2
2
2
1
0
0
0
0
0
2
0
0
0
0
0
0
2
0
0
0
0
0
0
|
2
2
2
2
2
2
0
0
0
0
1
2
0
0
0
0
1
2
0
1
2
2
1
0
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Key:
0 =
resistant
-
corrosion rate less than 100 mm/year
1 = partly
resistant
- corrosion
rate between 100 mm and 100 ..m/year
2 =
non-resistant
- corrosion
rate greater than 100 mm/year
Thermal
Processing
1.
Annealing. SX 317L is
annealed at 1 050 - 1 150oC and water
quenched, although thin sections may be air
cooled. Optimum corrosion resistance is obtained
after quenching from above 1 100oC .
2.
Stress Relieving. 200-400oC
followed by air cooling.
3.
Hot working
Initial forging and pressing:- 1 170oC
Finishing:- 950oC
Note: Soaking
times to ensure uniformity of temperature are up to 12
times that required for carbon steel.
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