Is it possible...yes. Is there a high likelihood of failure trying to propagate epicormic branches (i.e., cuttings) from a log...yes! Honestly, you're much better off just buying some seedings or samplings from a local nursery.
However, if you're truly interested in learning more about how to root hardwood cuttings, please view information from the following website:
For information on grafting black walnut scionwood to other rootstock, please review the following publications:
Best of luck!