PACE Technologies Home Page for metallographic equipment and consumables for metallography

Metallographic Etchants - Stainless Steel

| Home | Consumables | MSDS | Procedures | Equipment | Etchants | Contact us |

Metallographic Stainless Steel Etchants

Metallographic Etching

Stainless Steel Etchants

Etching stainless steels can be somewhat difficult due to the anti-corrosive nature of stainless steel. Austenitic or 300 series stainless steels typically have higher chrome as well as a significant amount of nickel (e.g. 304 stainless steel - 18% chrome, 8% nickel) which makes them harder to etch. Martensitic or 400 series stainless steels are easier to machine, however, they are not as corrosion resistant so they are easier to etch.

Sample Preparation: Stainless steels must be properly prepared to reveal the true metallographic microstructure. A number of recommended procedures can be found at the following links:

http://www.metallographic.com/Procedures/Stainless%20Steel%20Description.htm

http://www.metallographic.com/Brochures/Met-Manual-2b.pdf

CAUTION: Safety is very important when etching. Be sure to wear the appropriate protective clothing and observe all WARNINGS on chemical manufacturers MSDS. Also review COMMENTS Section for each etchant.

Etchant

Conc.

Conditions

Comments

Carpenter 300 Series
Stainless Steel Etchant

Ferric chloride
Cupric chloride
Alcohol
Hydrochloric acid
Nitric acid



8.5 grans
2.4 grams
122 ml
122 ml
6 ml
Immerse for several seconds. A nice etchant for 300 series, austenitic, duplex stainless steels
Kalling' No. 2
Cupric chloride
Hydrochloric acid
Alcohol

12 grams
20 ml
225 ml
Immerse or swab - seconds to minutes For 400 series or martensitic stainless steel

Modified Murakami's
K3Fe(CN)6
Potassium hydroxide
Distilled water


30 grams
30 grams
150 ml

1 second to several minutes by immersion or swabbing

Mix potassium hydroxide into water before adding K3Fe(CN)6.

Hydrochloric acid
Selenic acid
Ethyl alcohol

20-30 ml
1-3 ml
100 ml

Immerse at room temperature for 1-4 minutes

Color etching. Colors carbides and gamma prime phase in heat resisting steels

Ammonium bifluoride
Potassium metabisulfite
Distilled water

20 grams
0.5 grams
100 ml

Immersion at room temperature for 1-2 minutes

Color etching. Etching of austenitic stainless steel and welds. Reveals delta ferrite in welds.


Metallographic micrograph of etched stainless steel
431 Stainless Steel, etched with Modified Murakami's, Mag. 400X (DIC)


Copyright © 2006-2014
PACE Technologies - 3601 E. 34th St. - Tucson, AZ 85713 USA
Telephone +1 520-882-6598 FAX +1 520-882-6599.
All Rights Reserved.


PACE Technologies facebook link   Blog us on Tumblr   Blog us on Tumblr PACE Technologies Google+ PACE Technologies LinkIn