PROCESS - PLATING - CRACK - FREE CHROMIUM, CF-500, PHYSICAL AND CHEMICAL PROPERTIES, EVALUATION OF
GENERAL DYNAMICS CORP FORT WORTH TX
Pagination or Media Count:
Crack-free 500 Cr and conventional Cr plated 4130 and Thermold A steel H-11 type steel similar to Vascojet 1000 test specimens were plated and compared in various tests. The tests were crack detection, visual observations, adhesion, hardness, salt spray accelerated corrosion tests, sustained load tests, and effects of various bake-out conditions on H content in plated Thermold A steel. The two types of Cr were comparable in appearance and adhesion but CF-500 Cr was slightly harder and considerably more corrosion resistant in salt spray tests. It was also determined that increasing the H relief bake-out conditions produced adequate sustained load strength of CF-500 Cr plated high heat treat steel. H analysis test results on specimens with one or more unplated edges showed the H content was reduced by increasing the bake- out time and temperature. Adequate H embrittlement relief was obtained by baking at 500 F for 23 hr.
- Metallurgy and Metallography
- Coatings, Colorants and Finishes