Whilst the Akula-class attack subs (not to be confused with NATO-name Akula, the Typhoon SSBN - what this article is about) explicitly moved back to using steel after the Sierra-class used titanium due to cost, I used to work at BAE Systems on Submarine systems / weapons ~17 years ago, and I'd also heard rumours there that the inner hull was Titanium.
Whilst it's not likely that the mission could continue with damage from a Mark 46 (44 KG explosive, btw), it's very likely that the titanium would at least give the submarine a much greater chance of survival than otherwise, as evidenced by the USS Baton Rouge collision in February 1992 with a Sierra-class sub, which suffered much less damage than the American one.
Whilst it's not likely that the mission could continue with damage from a Mark 46 (44 KG explosive, btw), it's very likely that the titanium would at least give the submarine a much greater chance of survival than otherwise, as evidenced by the USS Baton Rouge collision in February 1992 with a Sierra-class sub, which suffered much less damage than the American one.