316 en 316L en 316 met Ti

Question 1

Wat is de reden dat Ti wordt toegevoegd aan de 316?

Answer 1

The addition of titanium is made to reduce the risk of intercystalline corrosion following heating in the temperature range 425-815 °C. Here 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 (Intercrystalline corrosion or “ICC”, also known in the past as ‘weld decay’).

Question 2

Wat is het alternatief voor legeren met Ti van 316 om ICC te voorkomen?

Answer 2

The alternative approach to reducing the risk of ICC attack is to reduce the carbon level to levels below 0.03%. In this way a grade of 316 is produced with, in practice, the same resistance to ICC as 1.4571 (316Ti/320S31).

Question 3

Wat zijn overwegingen om te kiezen voor 316L ipv 316Ti?

Answer 3

Geen specifiek voordeel in aqueous corrosion media
Some extra strength boven T=600C.
De 316Ti mayhave inferior impact properties.
Ti results in higher tool wear