Surface hardening at a bearing bush
Treatment : spheroidised / surface
hardened
Magnification : 12,5 : 1
Etching medium : 3 % alcoholic nitric acid
Sampling / Specification : transverse
Testing result :
effective hardening depth 2,25 mm
Treatment : spheroidised / surface hardened
Magnification : 50 : 1
Etching medium : 3 % alcoholic nitric acid
Sampling / Specification : transverse
Testing result :
transition area
left : hardness penetration zone ; martensite
right : basic material ; soft annealed structure