Etching chrome castings for inspection

We are looking at a project which will require chemically etching B50A178H material. Generic name is cast 2.25 Chrome, 1 Molybdenum Steel, to look for field welded areas. The welded areas may not be of a correct, or uniform material, but the base metal is. We know that etchants such as Nital will likely do the job but, we would like to use a chemical that is most friendly to both our employees, customers' employees, and the environment. Any suggestions would be greatly appreciated.

You may try with reverse current etch using a brush plating portable equipment. Vendors of such equipment have proprietary formulations that are friendly enough to be used within industrial plants and work well on most materials (ferrous and non).