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Avoiding cracks on chrome plated and ground surface

I have problem in chrome plating a large ring of size 500 mm dia., thickness 20 mm, width 25 mm. the material is carburising steel to french spec 16 NCD 13. After hard chrome plating the Plated surface is ground to achieve smooth surface finish. This surface is expected to be wear resistant. After grinding, Network crack pattern is noticed on the plated area. How to avoid this?

P.g.varghese
Plating shop - Bangalore, Karnataka, India
2004

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To avoid cracking. How hard is your part? Parts over HRC 52 needs a heat treatment steps in a lower temperature 142 °C. Has your parts been shoot peening before chrome plating? How deep is the grindings cuts? It should be min 2-3 µm. Has your parts a lots of chrome overhangs? Remove this slowly in the grinding operation. Also analyze the ratio between chrome and the sulfuric. High sulfuric can shows cracks.

Regards,

Anders Sundman
4th Generation Surface Engineering
Consultant - Arvika,
Sweden
2004