Porosity measurement on thermal sprayed coating of zinc analysis acc. to AWS C2.23m/NACE - question.

[Fikus]

hi,

I have to prepare a porosity test acc. to AWS C2.23m/NACE on zinc coating made on steel, but i have a few questions, I will be really grateful if You would like to answer me:

1. Metallograhic samlpe should be made on bend test, which was made on point 3.2.4 ?
1.2. Sample of bend test sample should be similar to 100x50mm/200x1.3mm, but how big is the testing zone ? Full dimentions (100x50/200x1.3) after 180* bending ?
3. Were can i get a% parameter? It described by AWS or customer order?
4. Porosity measurement could me made by graphic analysis on computer?

greets, and thanks for answer!
F

 

[CoCoE]

1. Yes
2. Bend it on 13mm mandrel. Bend test area is the area deformed. If you want to test porosity on bend plate, test it on intact zone of bend coupon. Bent or damaged or lifted zones should not be used to decide the porosity.
3. Keep it 15% as thumb rule, or do a test on your bend coupon.
4. Do Metallography; Magnification.

Regards

CocoE