Why Does AISI 1012 Have More Electrical Resistivity han AISI 1010 and AISI 1015

Maybe these numbers are in sequence based on something other than electrical resistivity? (Which, after all, is not usually the most important property of structural metals.)

Where did you get the numbers from. A specific sequence of tests? A handbook or standards of some sort?

AISI standards for plain carbon steels allow a certain range of important alloying elements and minimums of others. Content of higher resistivity materials such as carbon, phosphorus and sulfur can have effects on resistivity. Carbon content range is .05% for all three steels. That means they overlap for the three grades you cited. A given sample of 1010 may have more carbon than a sample of1012. All three allow a maximum of 0.40% to 0.50% in phosphorus and sulfur respectively. Therefore the aggregate of these elements can produce substantially different resistivities in two discrete samples from obviously different heats.

Impurities in small samples are also possible even within the allowances of the AISI specs and common mill practice. Any of these factors could affect the differences in resistivity.

Further, temperature differences of a few degrees can have marked effect on resistivity. Separate sets of test data that don't describe temperature information or comparable test protocols may lead one to believe they are equivalent when in fact they are not.

And finally, experimental error in testing is possible especially where data has not been subject to appropriate critical review.

Ed Weldon

EW is correct. Any properties whether mechanical, thermal, electrical or magnetic vary over a range except in pure elements/ compounds (There also you are likely to get a significant bit of difference due to heat treatment)

And that standardisation is definitely not existing in a solid solution.and that too with different cell configurations mixed.

The properties differ based on crystal structure (BCC, FCC,... each have there own properties, obviously the Diamond, carbon and Graphite or buckyball, all pure carbons, do not share common electrical properties) The difference between them is the crystal structure only.

As far as your question, I just tried to google the resistivity of AISI1010 (and one site said 17.5 μΩcm (max) against your post of 14.3 μΩcm.

_{There are quite a few papers on net discussing about the effect of microstructure on electro-magnetic properties of steel.}