ASTM No. 2

general purpose

Composition

4g Picric Acid, 100ml Ethanol

4%

Method

immersion

Time

10s

Basic Information

Category:General Purpose

Composition:4g Picric Acid, 100ml Ethanol

Concentration:4%

Reveals:Pearlite, cementite, grain boundaries

Typical Results:ASTM standard etchant for revealing pearlite structure. Does not attack ferrite grain boundaries as strongly as Nital.

Color Effects:Pearlite darkens, ferrite remains light