Thermal stress relief or baking for Hydrogen embrittlement is a process after plating to remove the hydrogen infused during the cleaning and plating process. Hydrogen embrittlement is a near ambient temperature phenomenon. The hydrogen gas bubbles form in the granular structure of the metal and causes embrittleness and premature failure of the part. Hydrogen Embrittlement Relief Milspec parts that meet or exceed Rc39 are required to undergo hydrogen embrittlement relief baked after coating. Hydrogen embrittlement gradually diminishes when the temperature is higher than 100 °C. Hydrogen embrittlement is caused by a wide range of factors and more importantly, requires specific treatment to be given to the materials based on how the embrittlement was caused. In the best case the hydrogen atoms are joined and released into the atmosphere as hydrogen gas. Most hydrogen embrittlement tests were conducted at ambient temperature. However, part of the H+ ions will be absorbed into the object, weakening its structure. Consider stress relieving and hydrogen de-embrittlement an absolute necessity, then, a process that releases the hydrogen by “baking” the part until it’s free of the gas. finishing.com - Pine Beach, New Jersey Striving to live Aloha Hydrogen embrittlement (HE) is a permanent loss of ductility in a metal or alloy that can lead to premature failures caused by the absorption of hydrogen in combination with stress, either externally applied or internal residual stress. Stress Relief as an Embrittlement Countermeasure That brittle state cannot be allowed, not when stress is part-and-parcel of structural engineering. Hydrogen ions from nitric and phosphoric acid in the coating bath find their way between the grains of the ferrous substrate when the parts are gassing. HE is not exclusive to electroplating let alone zinc electroplating, but can be caused by several different metal finishing and related processes. It involves the ingress of hydrogen into a component, an event that can seriously reduce the ductility and load-bearing capacity, cause cracking and catastrophic brittle failures at stresses below the yield stress of susceptible materials. Yes, the temperature and time you mentioned sounds appropriate for hydrogen embrittlement relief--just do it immediately after processing; don't wait a day or it will do little good. The risk of hydrogen embrittlement arises in all chemical processes where hydrogen is generated on the surface of the object. This is a type of deterioration which can be linked to corrosion and corrosion-control processes. But NO processing should ever be done in a kitchen or a food oven of any sort :-(Ted Mooney, P.E. Hydrogen Embrittlement (HE) refers to the increased internal stresses caused by hydrogen within the grain structure of ferrous articles. However, the most sensitive temperature for hydrogen embrittlement to occur is normally at sub-ambient conditions. Hydrogen embrittlement can also be formed in the metal during the casting and forging process. Hydrogen Embrittlement.