Baking custom 455 after pickle Baking custom 455 after pickle FWMengineering (Materials) (OP) 30 Jan 11 12:35 Is it really necessary to bake custom 455 at 300/350F after a acid pickle in HF and nitric?If it is needed what is the reasoning behind it? RE: Baking custom 455 after pickle RPstress (Aerospace) 31 Jan 11 09:13 Suggest you red flag this one and re-post in the Metal and Metallurgy forum. (Unless someone sufficiently knowledgable posts.)I think the bake is to remove hydrogen introduced during the pickling op, which can otherwise lead to hydrogen embrittlement. High strength stainless like Custom 455 is a bit vulnerable to that sort of contamination. However, those guys (metal and metallurgy) will know for sure. RE: Baking custom 455 after pickle 3 WKTaylor (Aeronautics) 31 Jan 11 10:10 Refer to AMS2759/9D Hydrogen Embrittlement Relief (Baking) of Steel Part, Table 1 TABLE 1 - MINIMUM BAKE SOAK TIME (HOURS) AT 375 °F (191 °C), Chemical treatments column "CHEM (3)". For Custom 455 in temper conditions H950 and H1000, there is a mandatory 3-hr bake @375 F beginning within 4-hrs after acid etch [pickling]. Regards, Wil TaylorTrust - But Verify!We believe to be true what we prefer to be true.For those who believe, no proof is required; for those who cannot believe, no proof is possible.