Study of the corrosion resistance of several stainless steels to zinc vapor revealed that some stainless steels could be employed for use in zinc processing equipment housings or vapor lines

Bennett, G. A.

Burris, L., Jr.

Nelson, P. A.

English

NASA Technical Reports Server

December 1967
	
Brief 67-10582 
dim AEC-NASA TECH BRIEF 	 Gf I-
AEC-NASA Tech Briefs describe innovations resulting from the research and development program 
of the U.S. AEC or from AEC-NASA interagency efforts. They are issued to encourage commercial 
application. Tech Briefs are published by NASA and may be purchased, at 15 cents each, from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Study Made of Resistance of Stainless Steels to Zinc-Vapor Corrosion 
Test Coupons Suspended 
By 20-mil Tantalum Wire 
Tantalum-Lined 
Vapor Chamber 
FurnaceZ 
Stainless Steel 
Tubing-Connection 
To Annulus 
Frozen 
Plug 
The problem: 
To determine the applicability of stainless steels for 
equipment which would be exposed only to zinc 
vapor, and not to zinc liquid. In recovering and 
purifying discharged reactor-fuel materials, the very 
corrosive zinc and zinc-rich alloys are employed as 
solvent media. Tantalum and tungsten vessels are used 
to hold the liquid zinc alloys; these vessels in turn 
are housed in stainless steel equipment. Although all 
stainless steels are severely attacked by liquid zinc, 
it has been observed that 304 stainless steel suffers 
little attack by zinc vapor at temperatures to about 
800°C.
Stainless Steel 
Thermocouple Well 
Stainless Steel Jacket 
Annulus 
To Vacuum
Pump 
Zinc-lO Percent 
;:sum A0y 
Tantalum-Lined 
Tubing 
The solution: 
A study of the corrosion resistance of several 
stainless steels to zinc vapor revealed that some 
stainless steels could be employed for use in zinc 
processing equipment housings or vapor lines. The 
stainless steels investigated were Types 405, 440C, 304, 
and 347. Type 405, a ferritic steel, appears definitely 
superior to the other steels tested in withstanding 
attack by zinc vapor. Type 440C, a martensitic steel, 
suffered considerable weight loss,' but no other 
discernible effects. Two austenitic stainless steels, 
Types 304 and 347, suffered severe intergranular 
attack and loss of nickel due to probable formation 
(continued overleaf) 
This document was prepared under the sponsorship of the Atomic 	 liability resulting from the use of the information contained in this 
Energy Commission and/or the National Aeronautics and Space document, or warrants that the use of any information, apparatus, 
Administration. Neither the United States Government nor any per- 	 method, or process disclosed in this document may not infringe pri-
son acting on behalf of the United States Government assumes any vately owned rights.
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of low melting, zinc-rich phases. Thus, from the stand-
point of structural integrity, both of the 400-series 
steels (405 and 440C) offer better resistance to attack 
by zinc vapor than do the 300-series steels. 
How it's done: 
The stainless steel test coupons were exposed to 
static zinc vapor for 500 hours at temperatures about 
9000 C .
 The apparatus, shown in the figure, consisted 
of a closed tantalum tube, jacketed in Type 304 stain-
less steel to prevent oxidation of the tantalum. A 
Zn-10 wt-pct Mg alloy charge in the bottom of the 
tube was maintained at about 740 1 C and provided 
zinc vapor at a partial pressure of about 70 mm Hg. 
Four weighed and measured stainless steel coupons 
were suspended in the vapor space in the upper part 
of the tantalum tube. This space was maintained at 
8900
 to 900°C, about 150°C above the dew point 
of the zinc vapor, to prevent condensation of the 
zinc vapor. Precautions were taken at the end of the 
run to prevent condensation during the cool-down 
phase. 
Throughout the run, the inner tantalum chamber 
was under vacuum, with the zinc alloy itself forming 
a freeze seal in the outlet tube. The annulus between 
the tantalum tube and the stainless steel shell was 
pressurized with high purity argon. 
At the conclusion of the test, the corrosion 
apparatus was sawed into two parts just below the 
test coupons, and the coupons were removed for 
determination of the extent of corrosion.
Notes: 
1. This information should be of general interest to 
the steel industry, and may be of specific interest 
to zinc alloy manufacturers, and to manufacturers 
of galvanized equipment, sheets, and parts. 
2. Additional details are contained in Transactions 
of the Metallurgical Society of AIME, vol. 233, 
May 1965, pp. 1032-103. 
3. Inquiries concerning this innovation may be di-
rected to:
Office of Industrial Cooperation 
Argonne National Laboratory 
9700 South Cass Avenue 
Argonne, Illinois 60439 
Reference: B67-10582 
Source: G. A. Bennett,

P. A. Nelson, and L. Burns, Jr.

Chemical Engineering Division

(ARG- 10055) 
Patent status: 
Inquiries about obtaining rights for commercial use 
of this innovation may be made to: 
Mr. George H. Lee, Chief 
Chicago Patent Group 
U.S. Atomic Energy Commission 
Chicago Operations Office 
9800 South Cass Avenue 
Argonne, Illinois 60439 
Brief 67-10582	 Category 03


Study made of resistance of stainless steels to zinc-vapor corrosion

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