The limit of hydrogen contents in Low Alloy Steel
The limit of hydrogen contents in Low Alloy Steel
(OP)
Hi All,
I am currently dealing with AISI 4130 and this material has hydrogen content of 0.16 ppm (max). I have read online that the hydrogen even at small amount will cause hydrogen embrittlement.
http://www.totalmateria.com/page.aspx?ID=CheckArti...
Therefore, I have some questions pertaining to that.
1. Why is there hydrogen contents in the low alloy steel? Under at what circumstances since it brings more negative impact to the steel material.
2. Is there a limit to the hydrogen contents? Where is this written or any documents to support it?
Thanks,
Jeffrey
I am currently dealing with AISI 4130 and this material has hydrogen content of 0.16 ppm (max). I have read online that the hydrogen even at small amount will cause hydrogen embrittlement.
http://www.totalmateria.com/page.aspx?ID=CheckArti...
Therefore, I have some questions pertaining to that.
1. Why is there hydrogen contents in the low alloy steel? Under at what circumstances since it brings more negative impact to the steel material.
2. Is there a limit to the hydrogen contents? Where is this written or any documents to support it?
Thanks,
Jeffrey





RE: The limit of hydrogen contents in Low Alloy Steel
Hydrogen typically comes from a pressurized process gas source (think of piping for that matter), but may also diffuse in the weld metal during welding.
RE: The limit of hydrogen contents in Low Alloy Steel
Thanks.
Thanks XL83NL. I am not sure about it. According to the materials spec and cert produced by the vendor, it has hydrogen element in it.
RE: The limit of hydrogen contents in Low Alloy Steel
http://amg-v.com/hydrogenpage.html
RE: The limit of hydrogen contents in Low Alloy Steel
In general, the issue of hydrogen in steel has been handled not by measuring hydrogen concentration in steel, but rather by limiting steel strength/hardness below certain limits and by using mechanical testing to verify lack of embrittlement. Some good standards on this subject are:
SAE/USCAR-5 Avoidance of Hydrogen Embrittlement of Steel
SAE/USCAR-7 Deembrittlement verification test
AMS2759/9 Hydrogen Embrittlement Relief (Baking) of Steel Parts
ASTM F519 Standard Test Method for mechanical hydrogen embrittlement evaluation of plating/coating processes and service environments
ASTM F1940 Standard Test Method for Process Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated Fasteners
ASTM F1624 Standard Test Method for Measurement of Hydrogen Embrittlement Threshold in Steel by the Incremental Step Loading Technique
RE: The limit of hydrogen contents in Low Alloy Steel
I wanted to note that the applicable compositional spec for AISI 4130 is UNS G41300, and it does not have any limitations on hydrogen. Sounds like this was a customer requirement or a restriction for an industry specification of some kind.
RE: The limit of hydrogen contents in Low Alloy Steel
mrfailure,
Yes, AISI 4130 is UNS G41300. Whether this material is a customer requirement or industry specification, as a materials engineer, we need to know the threshold limit (rough estimation) for hydrogen contents in steel. If we are not careful enough, hydrogen embrittlement, a common failure could occur at anytime; based on what I have read, it could occur in few hours while in some other cases, it may occur in several years.
Thanks,
Jeffrey