Industrial applications of AISI 316Ti

Knowledge base › Sheath materials › AISI 316Ti sheath material

What is AISI 316Ti?

AISI 316Ti (alternative names: S31635, 1.4571) is Cr-Ni-Mo austenitic stainless steel derivative of AISI 316. The difference lies in the addition of titanium to the alloy which guarantees that AISI 316Ti is stabilized and able to resist intergranular corrosion at temperatures between 426 and 815 °C, even for extended periods. This means that AISI 316Ti is suitable for welding without the loss of corrosion resistance. Titanium also increases mechanical strength, especially at temperatures above 800 °C.

AISI 316Ti has similar properties to AISI 316 as well as its other derivative, AISI 316L (1.4404). The addition of molybdenum provides these 316 alloys with excellent corrosion resistance, especially in chloride environments.

AISI 316Ti (and the other 316 alloys) are certified for use in the food industry due to their low reactivity and resistance to various aggressive substances including salt (water) and acids.

AISI 316Ti versus AISI 316L

These alternative alloys of AISI 316 have both been developed with the aim of making them better suited to welding by maximizing their intergranular corrosion resistance. The main difference lies in the way this is achieved. In AISI 316Ti, titanium is added for this purpose, while in AISI 316L, carbon is reduced to a maximum of 0,03% (the ‘L’ stands for low carbon). AISI 316L is a more recent development using new technologies that allow for the removal of carbon.

In most situations these two alloys are interchangeable, as they have almost identical characteristics. There are however a few notable differences:

AISIS 316Ti is better suited to high temperature environments as it can be held at high temperatures for a longer period of time than AISI 316L, without developing sensitivity to intergranular corrosion (a particular advantage for the food industry)
AISI 316Ti has slightly superior corrosion resistance
AISI 316Ti has better mechanical strength due to the higher carbon content and therefore the better choice when strength matters
The presence of titanium reduces the processability of AISI 316Ti and can cause wear in equipment due to the titanium carbo-nitrides
AISI 316Ti is more costly than AISI 316L
AISIS 316L is the better choice if corrosion resistance in water is required
Where a highly polished surface is required for the sheath material, then ASIS 316L may be preferable as the titanium carbo-nitrides can result in streaks on the surface.

AISI 316Ti physical properties

Composition (%)

Carbon (C) max:	0.08
Manganese (Mn) max:	2.00
Phosphorus (P) max:	0.045
Sulfur (S) max:	0.030
Silicon (Si) max:	0.75
Chromium (Cr):	16.0–18.0
Nickel (Ni):	10.0–14.0
Molybdenum (Mo):	2.00–3.00

Other properties

Yield Strength	205 MPa
Tensile Strength	515 MPa
Elongation (min.)	40%
Hardness	217 HBW
Density	7.9 g/cm3, 7900 kg/m3
Poisson’s ratio	0.28
Melting point	1375 °C
Expansion coefficient	16.5 10-6m (20 – 100°C)