I need to specify a field name different than the table for association

Question

Given I have an Artifact model and a User model: I would like to define two Artifact fields, opened_by and assigned_to, who values are User ids and inherit all of the proper association methods.

What is the proper belongs_to or has_one or has_many options I should set?

The goal is to be able to reference the user's name through the statement hld.assiged_to.name where hld is an artifact.

Thanks for the help. I've gotten myself confused with terminology with all of the reading i've done on the problem.