plating, anodizing, & finishing Q&As since 1989
Hydrogen Embrittlement - Lawrence gauge
Q. What is the alternative test for Hydrogen detection by Lawrence gauge method?
What is Boeing Porosity meter? What is alternative method to this too?
Materials & Processing engineer - India
November 1, 2022
A. Hello Mugunthan
Typically, there are no "official" alternative tests for Hydrogen Embrittlement. If some spec or purchasing order requires some specific test, it is difficult to bypass.
If I remember correct, methods that you had mentioned are intended to estimate how much Hydrogen is created during the plating process.
Currently, the most common method in the finishing industry is Hydrogen Embrittlement testing per ASTM F519. It includes plating and baking of specialized hardened, notched specimens. And after that, pulling them at a load close to the maximal tensile strength for 200 hours.
It simulates a worst case scenario on the most susceptible material.
As much as I know, all AMS plating specifications require such test to be performed at least monthly.
- Winnipeg, CANADA
Closely related historical posts, oldest first ...
Q. I'm working on some problems concerning hydrogen embrittlement. Reading some articles and searching the net for further information, I more and more often read about a "Lawrence gauge" that helps to control the hydrogen whether in the galvanizing bath or after the process.
Has anyone any suggestions where I can find information how this gadget works or where I can find a picture or even a supplier for this thing?
aircraft engines - Hamburg, Germany
A. ASTM F326 [affil. link to spec at Techstreet], "Standard Test Method for Electronic Measurement for Hydrogen Embrittlement from Cadmium-Electroplating Processes" describes this. It requires special equipment; a list of manufacturers is available from ASTM (one is www.lawrence-electronics.com)
A simplified summary: A metal shell (cylinder closed at one end and plugged at the other), masked off (painted) except for a specific area, is pretreated and plated. The shell is then rinsed and dried, and the plug is replaced with a vacuum ion gauge attachment. The cylinder is then heated (to a precise temperature) to facilitate the release of hydrogen into a vacuum. The recorded output gives both the rate and amount of hydrogen released.
The masking would not withstand the (hot dip) galvanizing process; perhaps you mean zinc electroplating? The method can test for hydrogen pickup from acid pickling and cathodic cleaning as well as from electroplating. "Hydrogen Embrittlement: A Guide for the Metal Finisher" by Craig Willan (available on the Internet) gives hydrogen absorbed from various acid treatments.
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
Ed. note: That hydrogen embrittlement article is long enough and detailed enough to be truly useful, while short enough to be read in fifteen or twenty minutes. Score another great reply from Ken Vlach. --Ted
Dear Marten Kleihauer
I am now looking at very similar issue that you were interested at the time. I need to measure hydrogen diffusion (uptake) and also hydrogen embrittlement of some specimens. Were you able to contact with this company? And did you have a chance to establish this kind of experimental set-up in your laboratory or facility? What can you say as advice or suggestion regarding this subject.
May 5, 2009