HOME FAQs BOOKS JOBS: Help Wanted Suggestions you are here: Hotline/Forum => Letter 29081

Phosphating of tool steel

++++

We use a casting of CH13 (hot worked tool steel investment casting)for our component making. This casting undergoes heat treatment (spherodising, machining, gas carburising, hardening and tempering, Hardness = 60 HRC) followed by sand blasting for surface cleaning.

While performing manganize phosphating, we find white patches. We are looking for a unifirm black colour. Can some one help to avoid white patches. Phosphating is followed by tectyl 272 oiling. Corrosion test (as per ASTM ASTM B-117 [link is to spec at TechStreet]) on the component with white patches show a good corrosion resistance.

G R Patel
Manufacturer, Power Equipments - Vadodara, Gujarat, India

ANSWER or FOLLOW UP POST an unrelated QUESTION HOT Topics

Disclaimer: It is not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information
presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The
internet is largely anonymous; some names may be fictitious and some recommendations may be deliberately harmful.

If you are seeking a product or service related to metal finishing, please check these Directories: