hua yi
Not really enough info.
A welder qualifying to AWS D1.5 Code is qualified to Process, material thickness, material range, and Position.
Same in AWS D1.1.
D1.5 is a bit more stringent in most respects I have found.
If you are involved in an audit the auditor will want to see dual welder qualification records if they are doing both type of code work.
I always qualified the welder to the D1.5 Code and would write one for D1.1 also if the essential variables were the same.
Again not enough info.
I hope this helps more than hurts.
Marshall