SEPARATION OF THE STRUCTURAL CONSTITUENTS OF THE Cr-Mn-N AUSTENITIC STEELS

Journal Article · Sat Dec 31 23:00:00 EST 1960 · Acad. rep. populare Romine, Studii cercetari met.

OSTI ID:4826010

Tuma, H; Loebe, K

The separation of the constituents of Cr--Mn--N austenitic steels is not possible electrolytically because the isolated product contains large quantities of mixed crystals. For this reason a method based on the high solubility of these steels in sulfuric acid is recommended. In this method a weighed sample of the material is exposed to 1:4 sulfuric acid heated to 40 deg C for ten minutes. At the end of this time the sample is removed from the solution and the isolated part is separated by centrifugation, washed with water, alcohol, and ether, and dried at 50 deg C in vacuum. Considering that sulfuric acid is a very active agent, the losses of isolated product do not exceed 2%. This method is not applicable to iron carbide, nor in the presence of vanadium. The structural stability of a Cr--Mn-- N austenitic steel could be determined using this method. If the steel is exposed to temperatures of 650, 700, and 800 deg C for a long period, the separation of the complex chromium carbide (M/sub 23/C/sub 6/) (M being Cr, Fe, or Mo) could be established during the first phase. After a prolonged anneal (more than 300 hr at 650 deg C and less than 50 hr at 800 deg C), chromium nitride is separated. This separation is still incomplete after 5000 hr of anneal. The mechanical properties and the corrosion resistance decrease sharply with the separation of the chromium nitride. (tr-auth)

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-16-004558
• OSTI ID: 4826010
• Journal Information: Acad. rep. populare Romine, Studii cercetari met., Journal Name: Acad. rep. populare Romine, Studii cercetari met. Vol. Vol: 6
• Country of Publication: Country unknown/Code not available
• Language: Rumanian

Related Subjects

AUSTENITE
CHROMIUM ALLOYS
CHROMIUM CARBIDES
CHROMIUM NITRIDES
CORROSION
CRYSTALS
ELECTROCHEMISTRY
HEAT TREATMENTS
IRON CARBIDES
MANGANESE ALLOYS
MECHANICAL PROPERTIES
METALS, CERAMICS, AND OTHER MATERIALS
MOLYBDENUM CARBIDES
NITRIDES
SEPARATION PROCESSES
SOLUBILITY
STEELS
SULFURIC ACID
VANADIUM ALLOYS