Hot Dip Galvanize 10.9 Threaded Stud Bolt

[bulldogwld]

Hello, while researching Hot Dip Galavanizing, I came across this thread.

thread330-48335

It expressed concern about hydgrogen embrittlement.

We are seeking to have a 10.9 grade steel threaded stud (M36x560mm) hot dip galvanized at a bath temp of about 850F, to ASTM A153 spec. In ASTM A153, sect 5.3, it covers possible Hydrogen Embrittlement. This section refers to ASTM A143.

In A143, section 4.2 it references steel exceeding 150 ksi. We are using a class 10.9 steel with these physical properties BEFORE galvanizing.
Tensile KSI 157.0
Yeild KSI 150.0
% Elongation 33.2
Reduction of area 53.0

What might be the problems we encounter with the properties of the steel AFTER hot dip galvanizing?

 

[CoryPad]

This subject is covered in the commentary of section 2.3.3 of the Specification for Structural Joints Using ASTM A325 or A490 Bolts, available from the Research Council on Structural Connections here:

http://www.boltcouncil.org/files/2004RCSCSpecification.pdf

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[dbooker630]

I would not expect the tensile or yield strength to drop, the ductility is what is affected. I would be more concerned if you had class 12.9 fasteners. As long as you follow proper procedures before, I would not expect any issues after. There is always the practice noted in 7.2 of A143 that could be used,