I have seen several technical papers on this subject where strain aging in carbon and low alloy steel can be significantly reduced by maintaining an approximate 3:1 ratio of AL:N. If the nitrogen content of the steel is inadvertently increased during steel production, this results in the formation of Fe4N (iron nitride) that will precipitate between 300 to 600 deg F, and tie up slip systems. This increases strength and reduces ductility in the steel.
Since you need to measure the aluminum and nitrogen contents of the steel, the only reliable method is to remove a sample and perform a chemical analysis.
