High strength low alloy steels Jobs were quenched and tempered to a hardness of 40-41 HRC. Subsequently they were cleaned by degreasing and pickling, then oxidized for corrosion protection. After the surface treatment they were supposed to be baked as soon as possible as per MIL-DTL-13924D. However, the baking process was carried out after 48 hrs (190 Celsius for 3 hrs and then cooed to RT).Parts are physically hardness tested individually and hardness was found b/w 39.5- 41 HRC. All parts are currently free of any surface cracking(after lapse of 27 days). Are they still susceptible to hydrogen embrittlement and cracking? how we can qualify by destructing some of the parts to assure that they are fit for use and are not prone to hydrogen embrittlment cracking? or they can only be rejected?
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