Baking

Controlling hydrogen embrittlement for a better product

During acid cleaning and electroplating of steel, Hydrogen can be introduced into the process. However, hydrogen inhibits the metals ability to deform, and the result is, the metal can break or fracture at a much lower load or stress than anticipated. As a result, the affects of hydrogen embrittlement on metals are a serious problem, especially in aircraft & aerospace component manufacturing. In a process known as embrittlement relief, or baking, the hydrogen can be released from the fastener and lower the susceptibility to hydrogen embrittlement.

Working to a higher standard

To help keep hydrogen embrittlement at a minimum in the plating process, Southwestern Plating considers ASTM F1941 as the standard specification for electrodeposited coatings on threaded fasteners. ASTM F1941 requires hydrogen embrittlement relief for fasteners with hardness of HRC 40 or above. Should they qualify, fasteners are to be baked within 4 hours after electroplating at temperatures of 350°F to 450°F.  There is no specified baking duration for fasteners but 2 to 24 hours may be suitable depending on the fasteners and processes involved. 

Southwestern Plating will consider 3 hours at 375°F as a minimum for quoting purposes only.  It is in the customers’ best interest that he/she specifies the exact time and temperature necessary for their parts.