Sanmac® 316/316L Bar

Datasheet updated

2022-06-29 15:14
(supersedes all previous editions)

Sanmac® 316/316L is a molybdenum-alloyed austenitic chromium-nickel steel with improved machinability. The grade is used for a wide range of industrial applications where steels of types ASTM 304/304L have insufficient corrosion resistance.

Typical applications for Sanmac® 316/316L are machined parts as fittings and flanges and components for valves and pumps.

Standards

  • ASTM: 316, 316L
  • UNS: S31600, S31603
  • EN Number: 1.4401, 1.4404
  • EN Name: X 5 CrNiMo 17-12-2, X 2 CrNiMo 17-12-2
  • W.Nr.: 1.4401, 1.4404

Product standards

  • EN 10088-3, EN 10088-5 (dimensions up to 250 mm)
  • EN 10272, EN 10222-5 (dimensions ≥ 180 mm), AD-2000-W2
  • ASTM A479, A276
  • Chemical composition and mechanical properties acc. ASTM A182

Approvals

Certificate

  • Status according to EN 10 204/3.1

Chemical composition (nominal)

Chemical composition (nominal) %
C Si Mn P S Cr Ni Mo
≤0.030 0.3 1.8 ≤0.040 ≤0.030 17 10 2.1

Chemical composition (nominal) %

C
Si
Mn
P
S
Cr
Ni
Mo
≤0.030 0.3 1.8 ≤0.040 ≤0.030 17 10 2.1

Applications

Sanmac® 316/316L is used for a wide range of industrial applications where steels of type AISI 304/304L have insufficient corrosion resistance.
Typical examples are: Machined parts for tube and pipe fittings, valves, components for pumps, heat exchangers and vessels, different tubular shafts
in chemical, petrochemical, fertilizer, pulp and paper and power industries as well as in the production of pharmaceuticals, foods and beverages.

Industrial categories Typical applications
Chemical industry
Flanges
Food industry
Valves
Petrochemical industry
Fittings
Pulp & paper industry
Couplings
Rings
Seals
Bolts and Nuts
Shafts
Discs

Corrosion resistance

General corrosion

Sanmac® 316/316L has good resistance to:

  • Organic acids at high concentrations and temperatures, with the exception of formic acid and acids with corrosive contaminants
  • Inorganic acids, e.g. phosphoric acid, at moderate concentrations and temperatures, and sulfuric acid below 20% at moderate temperatures. The steel can also be used in sulfuric acid of concentrations above 90% at low temperature.
  • E.g. sulfates, sulfides and sulfites
  • Caustic environments

Intergranular corrosion

Sanmac® 316/316L has a low carbon content and therefore good resistance to intergranular corrosion.

Stress corrosion cracking

Austenitic steels are susceptible to stress corrosion cracking. This may occur at temperatures above about 60°C (140°F) if the steel is subjected to tensile stresses and at the same time comes into contact with certain solutions, particularly those containing chlorides. In applications demanding high resistance to stress corrosion cracking, austenitic- ferritic steels, e.g Sanmac® 2205 or SAF™ 2507, have higher resistance to stress corrosion cracking than 316L.

Pitting and crevice corrosion

Resistance to these types of corrosion improves with increasing molybdenum content. Thus, the molybdenum-alloyed Sanmac® 316L/316L has substantially higher resistance to attack than steels of type AISI 304 and 304L.

Gas corrosion

Sanmac® 316/316L can be used in

  • Air up to 850°C (1560°F)
  • Steam up to 750°C (1380°F

Creep behavior should also be taken into account when using the steel in the creep range. In flue gases containing sulphur, the corrosion resistance is reduced. In such environments the steel can be used at temperatures up to 600–750°C (1110–1380°F) depending on service conditions. Factors to consider are whether the atmosphere is oxidizing or reducing, i.e. the oxygen content, and whether impurities such as sodium and vanadium are present.

Forms of supply

Finishes and dimensions
Sanmac® 316/316L bar steel is stocked in a large number of sizes. The standard size range for stock comprises 40-450 mm.
Round bar is supplied in solution annealed and peel turned condition.

Lengths
Bars are delivered in random lengths of 3-7 m, depending on diameter.

Straightness
Diameter
mm
Height of arch, mm/m
Typical value
20 - 70 1
> 70 2
Tolerances, mm sizes
Diameter, mm
Tolerances, mm
40-45
-0/+0.16
50-70
-0/+0.19
75-95
-0/+1.00
100-285
-0/+1.50
290-350
-0/+2.00
360-450
-0/+3.00
Surface conditions
Surface
conditions
Ra, µm
Typical value
Size, diameter, mm
Peeled and burnished
1
20-285
Peel turned 2 >285 - 350
Rough machined
5
>350

Heat treatment

Sanmac® 316/316L bars are delivered in solution annealed condition.

Solution annealing
1040–1100°C (1900–2010°F), rapid cooling in air or water.

Mechanical properties

Bar steel is tested in delivery condition.

At 20°C (68°F)

Metric units
Proof strength Tensile strength Elong. Contr. HB
Rp0.2a) Rp1.0a) Rm Ab) Z
MPa MPa MPa % %
≥205 ≥240 515-690 ≥40 ≥50 ≤215
Imperial units
Proof strength Tensile strength Elong. Contr. HB
Rp0.2a) Rp1.0a) Rm Ab) Z
ksi ksi ksi % %
≥29.5 ≥35 74.5-100 ≥40 ≥50 ≤215

1 MPa = 1 N/mm2
a) Rp0.2 and Rp1.0 corresponds to 0.2% offset and 1.0% offset yield strength, respectively.
b) Based on L0 = 5.65ÖS0 , where L0 is the original gauge length and S0 the original cross-section area.

Impact strength

Due to its austenitic microstructure, Sanmac® 316/316L has very good impact strength both at room temperature and at cryogenic temperatures.

Tests have demonstrated that the steel fulfils the requirements (60 J (44 ft-lb) at -196 oC (-320 oF)) according to the European standards prEN13445-2(UFPV-2) and EN 10272.

At high temperatures

Metric units
Temperature Proof strength Tensile strength
°C Rp.02 Rp1.0 Rm
MPa MPa MPa
min. min. min.
100 165 200 430
200 137 165 390
300 119 145 380
400 108 135 380
500 100 128 360
Imperial units
Temperature Proof strength Tensile strength
°F Rp.02 Rp1.0 Rm
ksi ksi ksi
min. min. min.
200 24.0 29.0 62.4
400 19.8 23.9 56.6
600 17.3 21.0 55.1
800 15.7 19.6 55.1
1000 14.5 18.6 52.2

Physical properties

Relativ magnetic permeability < 2,1
Density: 8.0 g/cm3 , 0.29 lb/in3
Thermal conductivity

Temperature Temperature
°C W/m °C °F Btu/ft h °F
20 14 68 8
100 15 200 8.5
200 17 400 10
300 18 600 10.5
400 20 800 11.5
500 21 1000 12.5
600 23 1100 13


Specific heat capacity

Temperature Temperature
°C J/kg °C °F Btu/lb °F
20 485 68 0.11
100 500 200 0.12
200 515 400 0.12
300 525 600 0.13
400 540 800 0.13
500 555 1000 0.13
600 575 1100 0.14


Thermal expansion, mean values in temperature ranges (x10-6)

Temperature Temperature
°C Per °C °F Per °F
30-100 16.5 86-200 9.5
30-200 17 86-400 9.5
30-300 17.5 86-600 10
30-400 18 86-800 10
30-500 18 86-1000 10
30-600 18.5 86-1200 10.5
30-700 18.5 86-1400 10.5


Modulus of elasticity, (x103)

Temperature Temperature
°C MPa °F ksi
20 200 68 29.0
100 194 200 28.2
200 186 400 26.9
300 179 600 25.8
400 172 800 24.7
500 165 1000 23.5

Hot working

Hot working should be carried out at a material temperature of 900-1200°C (1650-2190°F).
Hot-working of SANMAC® 316/316L shall be followed by rapid cooling in air or in water. If additional heat treatment is needed it should be carried out in accordance with the recommendations given for heat treatment.

Machining

Sanmac is our trademark for the Alleima machinability concept. In SANMAC materials, machinability has been improved without jeopardising properties such as corrosion resistance and mechanical strength.

The improved machinability is owing to:

  • optimised non-metallic inclusions
  • optimal chemical composition
  • optimised process and production parameters

Detailed recommendations for the choice of tools and cutting data regarding turning, thread cutting, parting/grooving, drilling, milling and sawing are provided in the brochure S-029-ENG. Figure 1 shows the ranges within data should be chosen in order to obtain a tool life of minimum 10 minutes when machining austenitic SANMAC materials (304/304L, 316/316L). The ranges are limited in the event of low feeds because of unacceptable chip breaking. In the case of high cutting speeds, plastic deformation is the most dominant cause of failure.

When feed increases and the cutting speed falls, edge frittering (chipping) increases significantly. The diagram is applicable for short cutting times. For long, continuous cuts, the cutting speeds should be reduced somewhat.

[bild] Figure 1. Machining chart SANMAC® 316/316L.

The lowest recommended cutting speed is determined by the tendency of the material to stick to the insert (built-up-edge), although the integrity of insert clamping and the stability of the machine are also of great significance.

It is important to conclude which wear mechanism is active, in order to optimise cutting data with the aid of the diagram.

Turning of SANMAC® 304/304L, 316/316L

Recommended insert and cutting data (starting values)

Insert
Geometry

Grade Cutting data
Feed
Cutting speed Application
mm/rev m/min
MF GC2015 0.15 250 Finishing, copy turning
MM GC2015 0.30 225 Medium machining
MM GC2025 0.30 195 Medium-to-rough machining under less stable conditions

Welding

The weldability of SANMAC® 316/316L is good. Suitable methods of fusion welding are manual metal-arc welding (MMA/SMAW) and gas-shielded arc welding, with the TIG/GTAW method as first choice.

Since this material is alloyed in such a way to improve its machinability, the amount of surface oxides on the welded beads might be higher compared to that of the standard 316L steels. This may lead to arc instability during TIG/GTAW welding, especially welding without filer material. However, the welding behavior of this material is the same as for standard 316L steels when welding with filler material.

For SANMAC® 316/316L, heat input of <2.0 kJ/mm and interpass temperature of <150°C (300°F) are recommended. Preheating and post-weld heat treatment are normally not necessary.

Recommended filler metals

IG/GTAW or MIG/GMAW welding

ISO 14343 S 19 12 3 L / AWS A5.9 ER316L (e.g. Exaton 19.12.3.L)

MMA/SMAW welding

ISO 3581 E 19 12 3 L R / AWS A5.4 E316L-17(e.g. Exaton 19.12.3.LR)

Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Alleima materials.