When is hydrogen embrittlement relief necessary for a plated P/M component?

When plating a powdered metal part of 6.80 density in either alloyed or pre-alloyed material or just iron carbon material do I need to be concerned about hydrogen embrittlement? the apparent hardness is below 320 HV. For a heat treated part of the same types of material and having an apparent hardness of less than 320HV do I need to be concerned about hydrogen embrittlement? When considering the application of hydrogen to a heat treated P/M part what hardness do I evaluate particle or apparent and this would be for all materials listed above. What standards would give me this information?

It is required when your customer or industry standard or specification calls out for it. Typically, you post plate bake when the hardness is hR 36 or higher. Use of the part, geometry, plated material all have a bearing on "Is It Necessary".