what is the difference in .step and .iges and .hm??
IGES and STEP are the widely used neutral CAD formats and accepted in all software. In IGES the output is in surfaces while STEP file keeps the assembly hierarchy and output is a mixture of solids/volumes and surfaces (only solids in most of the cases).
Link for importing .step file to Hyperworks : https://www.youtube.com/watch?v=LxH9atTeruM