316Ti Stainless Steel Pipe is a titanium stabilised version of 316 molybdenum-bearing austenitic stainless steel. The 316 alloys are more resistant to general corrosion and pitting/crevice corrosion than the conventional chromium-nickel austenitic stainless steels such as 304. They also offer higher creep, stress-rupture and tensile strength at elevated temperature. High carbon Alloy 316 stainless steel can be susceptible to sensitisation, the formation of grain boundary chromium carbides at temperatures between approximately 900 and 1500°F (425 to 815°C) which can result in intergranular corrosion. Resistance to sensitisation is achieved in Alloy 316Ti with titanium additions to stabilise the structure against chromium carbide precipitation, which is the source of sensitisation. This stabilisation is achieved by an intermediate temperature heat treatment, during which the titanium reacts with carbon to form titanium carbides. This significantly reduces susceptibility to sensitisation in service by limiting the formation of chromium carbides. Thus, the alloy can be used for extended periods at elevated temperatures without compromising its corrosion resistance. 316Ti has equvilent corrosion resistance to sensitisation as the low carbon version 316L.
Grade 316Ti stainless steel has been traditionally specified by German engineers and users with the Werkstoff number 1.4571.The former steel grade in the UK was 320S31.
This grade is essentially a standard carbon 316 type with titanium stabilisation and is similar in principle to the titanium stabilisation of the 304 (1.4301) type to produce 321 (1.4541). The addition of titanium is made to reduce the risk of intergranular corrosion (IC) following heating in the temperature range 425-815C.
Product Range
Specifications: ASTM A/ASME SA213/A249/A269/A312/A358 CL. I to V ASTM A789/A790
Sizes (Seamless): 1/2" NB - 24" NB
Sizes (ERW): 1/2" NB - 24" NB
Sizes (EFW): 6" NB - 100" NB
Wall Thickness available:
Schedule 5S - Schedule XXS (heavier on request)
Other Materials Testing:
NACE MR0175, H2 SERVICE, OXYGEN SERVICE, CRYO SERVICE, etc.
Dimensions:
All Pipes is manufactured and inspected/tested to the relevant standards including ASTM, ASME and API etc.
Background of 316Ti Stainless Steel Pipes
When austenitic stainless steels are subject to prolonged heating in the temperature range 425-815C, the carbon in the steel diffuses to the grain boundaries and precipitates chromium carbide. This removes chromium from the solid solution and leaves a lower chromium content adjacent to the grain boundaries. Steels in this condition are termed 'sensitised'. The grain boundaries become prone to preferential atack on subsequent exposure to a corrosive environment. This type of corrosion is known as intergranular corrosion (IC), also known in the past as 'weld decay'.
The addition of titanium reduces the risk of IC since titanium carbo-nitrides are formed in preference to chromium carbides which has the effect of maintaining the correct distribution of chromium throughout the structure of the steel. The result is that areas adjacent to grain boundaries, where the carbo-nitrides form, is not depleted of chromium to a level at which localised corrosion can occur in the grain boundary area.
The alternative approach to reducing the risk of IC attack is to reduce the carbon level to below 0.03%. In this way a grade of 316 is produced with, in practice, the same resistance to IC as 316Ti (320S31/1.4571). This is the basis of the 316L types (316S11/1.4404 and 316S13/1.4432).
Table 1. Composition ranges for 316Ti grade of stainless steels.
Grade | C | Si | Mn | P | S | Cr | Mo | N | Fe | Ni | Ti | |
316Ti | Min | - | - | - | - | - | 16.0 | 2.00 | - | Balance | 10 | 5x%(C+N) |
Max | 0.08 | 0.75 | 2 | 0.45 | 0.03 | 18 | 3.00 | 0.1 | Balance | 14 | 5x%(C+N) |
Table 2. Mechanical properties of 316Ti grade stainless steels.
Grade | Tensile Str (MPa) min |
Yield Str 0.2% Proof (MPa) min |
Elong (% in 50mm) min |
Hardness | |
Rockwell B (HR B) max | Brinell(HB) max | ||||
316Ti | 515 | 205 | 35 | 95 | 217 |
Note: 316H also has a requirement for a grain size of ASTM no. 7 or coarser.
Table 3. Typical physical properties for 316 grade stainless steels.
Grade | Density (kg/m3) |
Elastic Modulus (GPa) |
Mean Co-eff of Thermal Expansion (m/m/0C) | Thermal Conductivity (W/m.K) |
Specific Heat 0-1000C (J/kg.K) |
ElecResistivity (nΩ.m) |
|||
0-1000C | 0-3150C | 0-5380C | At 1000C | At 5000C | |||||
316/L/H | 8000 | 193 | 15.9 | 16.2 | 17.5 | 16.3 | 21.5 | 500 | 740 |
Table 4. Grade specifications for 316 grade stainless steels.
Grade | UNS No |
Old British | Euronorm | Swedish SS |
Japanese JIS |
||
BS | En | No | Name | ||||
316 | S31600 | 316S31 | 58H, 58J | 1.4401 | X5CrNiMo17-12-2 | 2347 | SUS 316 |
316L | S31603 | 316S11 | - | 1.4404 | X2CrNiMo17-12-2 | 2348 | SUS 316L |
316H | S31609 | 316S51 | - | - | - | - | - |
We export 316Ti Stainless Steel Seamless Pipe to Iran, Iraq, Oman, Qatar, Albania, Muscat, Bahrain, Turkey, Egypt, Maldives, Italy, UAE, Bahrain, Indonesia, Australia, Kuwait, Saudi Arabia, South Africa, Germany, UK, Denmark, Canada, USA, Peru, Brazil, Nizeria, Mexico, Venezuela (Latin America), South America, Russia, kazakhstan etc.
Prosaic Steel and Alloys is a well known worldwide exporter of Prosaic Steel and Alloys the highly acclaimed exporter 316Ti Stainless Steel Seamless Pipes, Prosaic Steel and Alloys is committed to provide each and every customer with the highest standard of customer service. We deals in 316Ti Stainless Steel Seamless Pipes in India & Overseas, offering a wide range of 316Ti Stainless Steel Seamless Pipes.