Steve, It is easy to determine the hardness of ferrous metals by a simple spark using a grinder to generate spark. See:
http://www.machinetoolrecyclers.com/spark-test.html A more definite test would be a Rockwell or Brinell hardness test.
https://www.reference.com/article/methods-testing-metal-hardness-7f201319634a9bcf?aq=how+to+test+hardness&qo=cdpArticles Hydrogen Embrittlement cannot occur if dipping solution does not contain hydrogen elements to be absorbed into metal at raised temps. Both acid and caustic cleaning dips can contain hydrogen atoms. BillTC 4926Odessa, Fl. [b]Steels[/b]If steel is exposed to hydrogen at high temperatures, hydrogen will diffuse into the
alloy and combine with
carbon to form tiny pockets of
methane at internal surfaces like grain boundaries and voids. This methane does not diffuse out of the metal, and collects in the voids at high pressure and initiates cracks in the steel. This
selective leaching process is known as
hydrogen attack, or high temperature hydrogen attack, and leads to
decarburization of the steel and loss of strength and ductility. Steel with an ultimate
tensile strength of less than 1000 MPa (~145,000 psi) or hardness of less than 32
HRC is not generally considered susceptible to hydrogen embrittlement. As an example of severe hydrogen embrittlement, the elongation at failure of 17-4PH precipitation hardened
stainless steel was measured to drop from 17% to only 1.7% when smooth specimens were exposed to high-pressure hydrogen. As the strength of steels increases, the susceptibility to hydrogen embrittlement increases. In high-strength steels, anything above a hardness of HRC 32 may be susceptible to early hydrogen cracking after plating processes that introduce hydrogen. They may also experience long-term failures anytime from weeks to decades after being placed in service due to accumulation of hydrogen over time from cathodic protection and other sources. Numerous failures have been reported in the hardness range from HRC 32-36 and more above; therefore, parts in this range should be checked during quality control to ensure they are not susceptible. [b]From:[/b]
mg-tabc@yahoogroups.com [b]On Behalf Of [/b]Steve S
mail@mgnuts.com [mg-tabc]
[b]Sent:[/b] Saturday, November 30, 2019 6:50 PM
[b]To:[/b] MG tabcgroups MG-tabc@yahoogroups.com>
[b]Subject:[/b] [mg-tabc] Spring Pivots Are the forward pivot mounts for the leaf springs hardened steel, heat
treated, or anything special? I'm about to get a frame acid dipped, and
hardened steel needs special care during the process to avoid hydrogen
embrittlement. I already have the rears removed but since the fronts
are such a pain to deal with I'd like to leave them in place if
possible. So I'd like to know what to tell the stripper he will be
dealing with. Or would I be better off removing them?
- Steve Simmons, TC8975, TC9849