The result of a cheapo alloy lockring and some overzealousness. It’s a Novatec track hub, 32H, and laced to Alex R450s as my beater bike. Not the best but it’s kept me happy.
Any suggestions?
Suggestion is a new hub dude… Do know of a repair good enough to have confidence in…
or you can get some liquid steel and apply it on the thread, then screw the cog back on.
it’s going to be kind of welded, safe enough but you won’t be able to take off the cog anymore.
this solution is very DIY and not recommended anyway, might be fine on a beater or a pub bike.
fixed 
got a quality all-city steel lock ring, greased up the threads, chased them back slowly without forcing anything. the solution is to stay off cheapo alloy rings, they are nothing but trouble