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
- TÜV AD-Merkblatt W0/TRD 100
- Pressure Equipment Directive (2014/68/EU)
- DNV, dimensions up to 450 mm
- Pre approval for PMA
Certificate
- Status according to EN 10 204/3.1
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
Sandvik 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 Sandvik Sanmac 316L/316L has substantially higher resistance to attack than steels of type AISI 304 and 304L.
Gas corrosion
Sandvik 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.
| Diameter mm |
Height of arch, mm/m Typical value |
|---|---|
| 20 - 70 | 1 |
| > 70 | 2 |
|
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 |
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)
| Proof strength | Tensile strength | Elong. | Contr. | HB | |
|---|---|---|---|---|---|
| Rp0.2a) | Rp1.0a) | Rm | Ab) | Z | |
| MPa | MPa | MPa | % | % | |
| ≥205 | ≥240 | 515-690 | ≥40 | ≥50 | ≤215 |
| 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, Sandvik 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
| 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 |
| 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 |
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)