STAINLESS STEEL Grade 316, 316L

s31600/EN 1.4401 S31603/EN 1/4404

Introduction:
Types 316, 316L are molybdenum-bearing austenitic stainless steels. These steels contain a higher percentage of nickel than
304SS. The resultant composition gives these steels much improved corrosion resistance in many aggressive environments.
The molybdenum addition ensures more resistance to pitting and crevice corrosion in chloride-containing media, sea water
and chemical environments such as sulfuric acid compounds, phosphoric and acetic acids. The lower rate of general
corrosion in mildly corrosive environments gives the steel good atmospheric corrosion resistance in polluted marine
atmospheres.

316 SS offers good strength and creep resistance and also possesses excellent mechanical and corrosion-resistant proper-
ties at sub-zero temperatures. 316L is a low-carbon modification of 316. The control of the carbon to a maximum of 0.03%
minimizes the problem of carbide precipitation during welding and permits the use of the steel in the as-welded condition
in a wide variety of corrosive applications.

Additionally, 316/316L is available in pipe and tube chemistry specification.

Product Range:
Product is available in Cold Rolled, Continuous Mill Plate and Plate Mill Plate form up to 60' wide in various thicknesses.

Certification:
ASTM A240, A480/09, A666, ASME SA240, SA480, SA666, ASTM A262, EN 10088-2, EN 10028-7.

Chemical Composition:

UNS/Euro Astm/Euro Carbon Manganese Phosphorous Sulfur Silicon Chromium Nickel Nitrogen Molybdenum
S31600 316 0.08 max 2 max 0.045 max 0.03 max 0.75 max 16-18 10-14 0.1 max 2-3
S31603 316L 0.03 max 2 max 0.045 max 0.03 max 0.75 max 16-18 10-14 0.1 max 2-3
X2CrNiMo17-12-2 1.4404 0.03 max 2 max 0.045 max 0.015 max 0.75 max 16.5-18.5 10-13 0.1 max 2-2.5
X5CrNiMo17-12-2 1.4401 0.07 max 2 max 0.045 max 0.015 max 0.75 max 16.5-18.5 10-13 0.1 max 2-2.5

Mechanical Properties:

Tensile Strength min Yeild Strength min Elongation min Hardness max
316 75 ksi 30 ksi 40% 95 HRB
316L 70 ksi 25 ksi 40% 95 HRB
1.4404 75 ksi 34.81 40%
1.4401 75 ksi 34.81 40%

Note: Enhanced properties available upon request.

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 STAINLESS STEEL Grade 316, 316L

Properties at elevated temperature:

The properties quoted below are typical of annealed 316 only, as strength values for 316L. fall rapidly at temperatures
above 800°F. These values are given as a guideline only, and should not be used for design purposes.

Short Time Elevated Temperature Tensile Properties:

Temperature °C
Temperature [ °C ] 100 300 500 600 700 800 900 1000 1100

Tensile Strength [MPa] 540 500 480 450 350 205 100 50 25

0.2% Proof Stress [MPa] 235 165 145 140 130 115

Elongation [% in 50mm] 52 48 47 44 43 42 63 62 76

Maximum Recommended Service Temperature (In oxidising conditions)

Operating Conditions Temperature [ °C ]

Continuous 920
Intermittent 870

Representative Creep Rupture Properties:

Stress [MPa] to Produce 1% Strain Stress [MN] to Produce Rupture

Temperature °C 10000 hours 100000 hours 1000 hours 10000 hours

550 225 125 320 270

600 145 80 220 170

650 95 55 160 110

700 65 35 110 70

750 40 20 75 45

800 30 15 55 30

850 20 10 35 20

Properties at Sub-Zero Temperatures

The properties quoted below are typical annealed CS316 only

Temperature [°C] 20 0 -10 -50 -140 -196

Tensile Strength [MPa] 584 680 832 1105 1136 1360

0.2% Proof Stress [MPa] 235 260 336 380 417 444

Elongation [% ] 61 70 69 65 61 58

Impact Energy [J] 170 191 186 183 155 166

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 STAINLESS STEEL Grade 316, 316L

Physical Properties:
The values given below are for 20°C, unless otherwise specified.
CS304
Density 8000kg/M³

Modulus of Elasticity in Tension 193GPa

Modulus of Elasticity in Torsion 70GPa

Poisson’s Ratio 0.25

Specific Heat Capacity 500J/kgK

Thermal Conductivity: @ 100°C 16.2W/mK

@ 500°C 21.5W/mK

Electrical Resistivity 740ným

Mean Co-efficient of Thermal Expansion: 0-100°C 15.9µm/mk

0-315°C 16.2µm/mk

0-540°C 17.5µm/mk

0-700°C 18.5µm/mk

Melting Range 1390-1430°C

Relative Permeability 1.02

(Note: this grade is non-magnetic becoming slightly magnetic after cold working)

FATIGUE CONSIDERATIONS
When looking into the fatigue of austenitic stainless steels, it is important to note that design and fabrication—not material—are the
major contributors to fatigue failure. Design codes (e.g.. ASME) use data from low-cycle fatigue tests carried out on machined specimens
to produce conservative S-N curves used with stress concentration factors (11c) or fatigue strength reduction factors (kt). In essence, the
fatigue strength of a welded joint should be used for design purposes, as the inevitable flaws (even only those of cross-sectional change)
within a weld will control the overall fatigue performance of the structure.

ANNEALING
Annealing of types 316 and 316L is achieved by heating to above 1900°F and for 60 minutes per inch thickness followed by water or air
quenching. The best corrosion resistance is achieved when the final annealing temperature is 1950'F_ Controlled atmospheres are
recommended in order to avoid excessive oxidation of the surface_ Temperatures above 1975°F are not recommended, except when
wire is strand annealed in controlled atmosphere.

STRESS RELIEVING
The lower-carbon-grade 316L can be stress relieved at 850°F to1100°F for 60 minutes with little danger of sensitization. A prolonged heat
treatment at these temperatures also results in sigma phase formation and change in the ductility of the material.

HOT WORKING
316 can be readily forged, upset and hot headed. Uniform heating of the steel in the range of 2100'F to 2300°F is required_ The finishing
temperature should not be below 1650°F_ Upsetting operations and forgings require a finishing, temperature between 1700°F and
1800°F_ Forgings should be air cooled_ All hot-working operations should be followed by annealing, pickling and passivation to restore
the mechanical properties and corrosion resistance.

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 STAINLESS STEEL Grade 316, 316L

COLD WORKING
31613161, types, being extremely tough and ductile, can be readily cold worked such as wire drawing, swaging and cold heading etc.
without difficulty. Severe cold forming may require intermediate annealing.

MACHINING
Like all the austenitic steels, this alloy group machines with a rough and stringy su-arf. Rigidly supported tools with as heavy a cut as
possible should be used to prevent glazing. Buymetal provides 316L grade bars suitable for machining.

WELDING
316/3161, types have good welding characteristics and are suited to all standard welding methods. Either matching or slightly
over-alloyed filler wires (e.g. ERW 309Mo) shouldbe used For maximum corrosion resistance, regular 316 should be annealed after
weldingto dissolve any chromium carbides which may have precipitated. The weld discoloration should be removed by pickling and
passivation to restore maximum corrosion resistance.

STRESS CORROSION CRACKING

Stress corrosion cracking (SCC) can occur in austenitic stainless steels when they are stressed in tension in chloride environments at
temperatures in excess of about 140°F. The stress may be applied, as in a pressure system, or it may be residual arising from
cold-working operations or welding. Additionally, the chloride ion concentration need not be very high initially, if locations exist in which
concentrations of salt can accumulate. Assessment of these parameters and accurate prediction of the probability of SCC occurring in
service is therefore difficult.
Where there is a likelihood of SCC occurring, a beneficial increase in life can be easily obtained by a reduction in operating stress and
temperature. Alternatively, specially designed duplex grade 2.205 should be used.

300

250
SCC

200
CS2205
Temperature (°C)

150

100

CS304L
CS316L
50

No SCC
0
0.0001 0.001 0.01 0.1 1 10

CI - (%)

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 STAINLESS STEEL Grade 316, 316L
ATMOSPHERIC CORROSION
The atmospheric corrosion resistance of austenitic stainless steel is unequalled by virtually all other uncoated engineering materials.
Stainless steel develops maximum resistance to staining and pitting with the addition of molybdenum. For this reason, it is common
practice to use these grades in areas where the atmosphere is highly polluted with chlorides, sulfur compounds and solids, either singly
or in combination.

INTERGRANULAR CORROSION
Sensitization may occur when the heat-affected zones of welds in some austenitic stainless steels are cooled through the sensitizing
temperature range of between 850' and 1550°F. At these temperatures, a compositional change may occur at the grain boundaries. If a
sensitized material is then subjected to a corrosive environment, intergranular attack may be experienced. This corrosion takes place
preferentially in the heat-affected zone away from and parallel to the weld. This form of attack is often termed “weld decay”.

316 SS has reasonable resistance to carbide precipitation. However, 316L grade should be specified for welded structures unless the
higher-carbon types are required for their increased strength.

CORROSION RESISTANCE
55316 types have superior corrosion resistance to 55304 types. SS316 has good resistance to most complex sulfur compounds such as
those found in the pulp and paper industry. C83 16 also has good resistance to pitting in phosphoric and acetic acids. 55316 has excellent
resistance to corrosion in marine environments under atmospheric conditions.

SULPHURIC ACID NITRIC ACID HYFROCHLORIC ACID

120 120 120

100 100 100

Temperature (°C)

Temperature (°C)

Temperature (°C)
80 80 80

60 60 60

40 40 40

20 20 20
0 20 40 60 80 100 0 20 40 60 80 100 0 5 10 15 20
% Acid by Weight % Acid by Weight % Acid by Weight

PHOSPHORIC ACID ACETIC ACID KEY

120 120 mils per year mm per year

100 100 <4 <0.1

Temperature (°C)

Temperature (°C)

80 80
4-40 0.1-1
60 60

40 40 >40 >1
20 20
0 20 40 60 80 100 0 20 40 60 80 100
% Acid by Weight % Acid by Weight

PITTING CORROSION
Pitting resistance is important, mainly in applications involving contact with chloride solutions, particularly in the presence of oxidizing
media_ These conditions may be conducive to localized penetration of the passive surface film on the steel, and a single deep pit may
well be more damaging than a much greater number of relatively shallow pits. The addition of molybdenum to the steel ensures that
316 has good resistance to localized corrosion such as pitting and crevice corrosion. The diagram below shows the critical temperature
for initiation of pitting (CPT) at different chloride contents for 304, 316 and 2205 types.

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 STAINLESS STEEL Grade 316, 316L

100
Pitting

80

CS2205
CPT (°C), 300mV SCE

60
CS316

40

CS304

20

No Pitting

0
0.01 0.02 0.05 0.10 0.20 0.50 1.0 2.0

CI (%)

Critical pitting temperatures (CPT) for 304, 316 and 2.205 at varying concentrations of sodium chloride (potentio-static determination
at + 300 mV SCE SCE). pH=6.0.
Pitting- resistance equivalent numbers (PREN) are a theoretical way of comparing the pitting corrosion resistance of various types of
stainless steels, based on their chemical compositions. The PREN (or PRE) numbers are useful for ranking and comparing the different
grades, but cannot be used to predict whether a particular grade will be suitable for a given application, where pitting corrosion may
be a hazard.

Typical PREN and comparison are shown below.

PREN Austenitic Stainless

26.50

23.50
PREN

20.50

17.50
316L 304 301 201LN 201

OXIDATION
3161316L has good oxidation resistance in intermittent service up to 1600°F and in continuous service to 1700°F. Continuous use of
type 316 in the 850° F to 1550°F temperature range is not recommended due to possibility of carbide precipitation but performs well
in temperatures fluctuating above and below this range. One should use the 316L in these applications.

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 STAINLESS STEEL Grade 316, 316L

DISCLAIMER:
The information provided in this data sheet was designed for Buymetal.com customers.
This information should not be used or relied upon for any specific or general application without an expert advice. Buymetal.com
disclaims any responsibility as to the suitability of the material, as there is limited information as to the application and the uses.
The information contained in this datasheet is not comprehensive nor an exhaustive statement of all relevant material applicable to
special and general metal products, and no representation, condition or warranty, that are implied or is given as to the accuracy or
completeness of this datasheets. Buymetal.com disclaim any liability for any direct, indirect, or consequential loss, damage or injury
suffered by any person, caused as a result of relying on any statement in or omission to this datasheet. Buymetal.com shall not be
liable in the event of a breakdown, malfunction or failure occurring due to faulty design, material or workmanship of the metal,
whether based on the information contained herein or not and shall not under any circumstances be liable for any damages,
either direct or indirect, particularly consequential damages including but not limited to damages for loss of profit.

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