Hydrogen embrittlement is the condition in which hydrogen that enters the metal during production processes leads to sudden and unexpected fractures, particularly in high-strength steels.
It is a critical topic in automotive because the fracture usually occurs after the part has been assembled and put under load, without any visual warning.
How does it occur?
Hydrogen released during operations such as acid cleaning, degreasing and electrolytic plating can enter the structure of the metal. In high-strength steels this hydrogen creates crack initiation under stress.
How is it prevented?
The basic method is baking (embrittlement relief) after plating at a defined temperature and duration. Baking must be started within a defined time after plating; delay reduces its effectiveness.
For this reason, oven temperature control, calibration of temperature measurement equipment and baking records are critical control points in plating plants.
Its place in audits
Temperature-controlled processes and the related measurement equipment requirements are evaluated within the scope of the CQI-11 Plating System Assessment. This topic is among the most frequently questioned in both the annual self-assessment and customer audits: which parts are baked, with which parameters, how soon after plating it is started, where the records are kept and how the temperature measurement system is verified.
Related training: CQI-11 training — temperature-controlled processes, measurement equipment requirements and record structure are addressed from the auditor’s perspective.