SQL Server - Is there any way to recover a corrupted database without backup?

Try to use these commands on the master database. It will reset the state of the database so you can work with it. This will put it into SINGLE USER MODE and ROLLBACK pending changes. After repair it will allow MULTIUSER AGAIN.

EXEC sp_resetstatus 'yourDBname';
ALTER DATABASE yourDBname SET EMERGENCY
DBCC checkdb('yourDBname')
ALTER DATABASE yourDBname SET SINGLE_USER WITH ROLLBACK IMMEDIATE
DBCC CheckDB ('yourDBname', REPAIR_ALLOW_DATA_LOSS)
ALTER DATABASE yourDBname SET MULTI_USER