what test is there to check if steel has been normalised.
what test is there to check if steel has been normalised.
(OP)
I don't know if I'm been led down the garden path or not but what test's are there to see if L.C.S has been normalised or stress relieved, and where can I get info on the subject thats worthy.
any help would be appreciated.
any help would be appreciated.





RE: what test is there to check if steel has been normalised.
Can you provide some additional information regarding your specific problem? This could help provide a specific answer to your question. Normalizing and stress relief are two completely different concepts.
Normalizing is a heat treatment method that involves heating carbon steel to about 1500-1600 deg F and cooling in air. A stress relief heat treatment, by comparison, involves heating the steel at lower temperature (below 1300 deg F) and also cooling in air.
The specific difference between these two methods is that normalization is a heat treatment that will affect the mechanical properties of the steel, whereas a stress relief operation typically removes residual stress induced by welding or machining operations. Stress relief will affect the hardness of the steel if it has been welded because stress relief can also be called post weld heat treatment. This is designed to reduce residual stresses and the hardness of the weld metal and the heat affected zone - stress relief temperature is normally selected so it will not affect the bulk mechanical properties of the steel. If the steel has not been welded and your objective is to remove residual stresses from machining, a stress relief operation should not result in change of hardness or mechanical properties of the steel.
RE: what test is there to check if steel has been normalised.
For example I beam material will present elongated grains.
The grains would not to be elongated if the I beam was normalised. I have no idea why anyone would want to normalise an I beam.
RE: what test is there to check if steel has been normalised.
RE: what test is there to check if steel has been normalised.
RE: what test is there to check if steel has been normalised.
RE: what test is there to check if steel has been normalised.
Select a sample of flat bar, prior to cold bending, to obtain a baseline hardness. After cold bending, perform the stress relief at 650 deg C, and conduct hardness testing at a location adjacent to and away from the outer radius of the bend on the flat bar. Perform hardness testing at the same locations on a second flat bar after cold bending that you suspect was heated to 850 deg C to 900 deg C, and air cooled (normalized).
If a normalization heat treatment did occur it should result in uniform hardness adjacent to and away from the outer bend radius of the flat bar. The hardness of the normalized flat bar away from the bend may also be affected, which is the reason for obtaining the baseline hardness. The flat bars that were cold bent and subjected to only a lower temperature stress relief operation should see some variation in hardness along the outer bend radius.
I would strongly suggest you send out your test pieces for hardness testing to a reputable metallurgical test lab.
RE: what test is there to check if steel has been normalised.
1) Grain refine, ASTM 6 or larger would be typical
2) Homogenize through the phase transformation process
3) Relieve residual stress if present
4) Improve fracture toughness
Having a fine grain size is not proof of normalizing, but having large grains is proof of not-normalizing.
Meeting impacts is much more likley if normalized, but failure to meet impacts is not proof of failing to normalize.