|
Letter 40068
How to judge whether plating passes B117 12
hours or 96 hours?
++++++
Many times I saw clear zinc plating can pass
B-117 [link is to spec at TechStreet] 12 hours and yellow
zinc plating can pass B117 96 hours. According to
B-633 [link is to spec at TechStreet], it does.
but I have question, what does B117 12 hours or B117 96 hours mean
since B117 is just a test method and doesn't specify the rusting
degree (the rusting degree specified by
D610 [link is to spec at TechStreet] ) ?
I just want to know at how much rust area is allowed to pass B117 12
hours test ? Can you guys please tell me?
thanks,
John
Nabob - ShenZhen, China
++++++
No rust is permitted.
Corrosion resistance requirements are given in ASTM B633 "Standard
Specification for Electrodeposited Coatings of Zinc on Iron and
Steel." After salt spray, Types II & III coated specimens "shall
show neither corrosion products of zinc nor basis metal...visible to
the unaided eye at normal reading distance" except white corrosion at
edges.
|
Ken Vlach
- Goleta, California
|
|
-
-
 |