Chemical extraction of precipitates from the steels
Chemical extraction of precipitates was performed on the bulk steel specimens.

Each sample was then placed in 500 ml of Berzellus reagent consisting of 1.85 liters H20, 320 gm cupric chloride, 280 gm potassium chloride, 1.5 ml hydrochloric acid and 20 gm of tartoric acid. Another composition is: 160g CuCl2, 140g KCl, 10g tartaric acid, 925mL distiled water and 75mL HCl.

The sample was placed on a vibrating table to enhance dissolution. Solution filtration was then used to filter carbides from the solution. The filter paper was washed (100 ml of .25 N HCL and 50 ml H20 ), then dried at 120°C before final weighing.

Another method for carbonitride precipitates: Chemical dissolution was used for all steels to extract the Ti and Nb carbonitride precipitates using an HCl acid solution at 65-70°C (1:1 mixture by volume of HCl acid, with a specific gravity 1.19, and distilled water). After the steel matrix was dissolved, a centrifuge was used to separate solid particles from the solution.

Carbide size and structure were determined by standard scanning electron microscopy and x-ray diffraction techniques.

For more information see the article, J. Lu, D.G. Ivey, H. Henein, J.B. Wiskel and O. Omotoso, EXTRACTION AND CHARACTERIZATION OF NANO-PRECIPITATES IN MICROALLOYED STEELS, Proceedings of IPC2008, 7th International Pipeline Conference, September 29 – October 3, 2008, Calgary, Alberta, Canada.

Terms of Use. Copyright © 2009 by Henrik Kaker. All Rights Reserved.