Identify the affected material and location. A corroded frame, stained glass and a cracked surface require different assessments.
What the observation means
Do not remove the frame or scrape deeply to measure the corrosion. The surrounding seal and fixing arrangement may be involved.
A useful next step
Follow only approved surface care and retain information about cleaners used. If there are sharp edges, loose parts or moisture entering beneath, stop using the hob and request help. Ordinary paint or sealant should not be used to conceal damage around a hot fitted appliance.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.