Prior-Austenite Grain Boundaries Etch, 500 mL



This product is a saturated aqueous picric acid solution with a small amount of wetting agent. It is commonly used to reveal prior-austenite grain boundaries of martensitic or bainitic steels if phosphorus is present in the steels. This formula is a modified version of ASTM standard E 407 number 81. We use dodecylbenzene sulfonate as the wetting agent instead of the tridecylbenzene, performance is the same.

  • Option: If the steel has more than 1% of chromium, add a small amount of hydrochloric acid to increase the effectiveness.

User Instructions:

The specimens must be properly prepared for metallographic studies to a very high-quality level before etching. Room temperature etching is most common but heating (up to 85°C) can make it more effective. Do not boil it. Immerse the sample for 1-60 minutes with occasional swabbing for heavier grain boundary attack. After etching, some light back-polishing with alumina slurry will remove the surface smut and improve the visibility of the grain boundaries.


Nalgene® Leakproof Bottle, HDPE.

Additional information

Weight 1.5 lbs
Dimensions 4.4 × 3.5 × 6.5 in
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