The invention discloses a freeze-
etching agent of ultra-low-
carbon steel casting billet macrograph
grain structure, and a preparation method thereof. The freeze-
etching agent is prepared from materials of: 30 to 50g of
ferric chloride, 0.5 to 1.2g of stannous
chloride, 2 to 3 parts of trinitrophenol, 10 to 20ml of
sodium alkyl phenyl
sulfonate, 200 to 500ml of absolute
alcohol, and 600 to 1000ml of
hydrochloric acid.
Solid agents of the formulation are mixed and placed into a
glass vessel according to the ratio; 1500 to 2000ml of
distilled water is divided into two parts; one part is added to the
solid mixed agents, and the other part is preserved for later use; absolute
alcohol is added to the preserved part of
distilled water;
hydrochloric acid is added to the
alcohol solution;
sodium alkyl phenyl
sulfonate is added to the
aqueous solution containing agents such as
ferric chloride, and the mixture is uniformly stirred; the alcohol +
hydrochloric acid solution is then added to the
aqueous solution containing the agents such as
ferric chloride; the solution is sufficiently stirred, such that the freeze-
etching agent is prepared. With the freeze-etching agent, the form of the ultra-low-carbon
continuous casting steel billet macrograph
grain structure can be clearly shown. The freeze-etching agent provided by the invention has advantages of high detection speed, low
pollution, and convenient operation. Also, the freeze-etching agent is energy-saving.