Yes, It is possible to create forum free.
1. Register on this site: www.proboards.com. Choose a domain. Type: your name, surname, email, and password.
2. Go to your email and you will get confirmation link. Click it and your forum will be active. It is that simple.
3. Go to your admin panel. Edit forum as you want. Make categories, choose a theme, and share it on social networks.
Here is my forum. Only for example: http://crotalk.boards.net