MICRO-ZONE ANALYSIS OF CARBIDES ON THE FRACTURE SURFACE OF MOLYBDENITIC STEELS (in Russian)
It was previously established that cracks and fractures in steels often originate at the grain boundaries where alloying additives and carbides are usually considerably enriched. This question was investigated in the case of steels containing Mo and Cr- Mo- Ni additions. Fractured spectmens were covered with an insulating layer except on the fracture face, which served as the anode of an electrolytic cell, the cathode was a Pt wire, 0.01 N HCl solution served as electrolyte. The cathodic depcsits were analyzed microchemically for the elements of the solid solution. The MoC was determined by treating the fracture with a hot mixture of H/sub 2/O/sub 2/ and alcohol, evaporating the solution to dryness and melting the residue with KNaSO/sub 4/ preparatory to microchemical analysis. For comparison, the unfractured surface was dissolved to a depth of 3 to 4 ation , about 2 mg of the metal, and used for zone-melting analysis. In many cases the difference between the two sets of values depended primarily on the steel composition and its thermal history. However, in steels containing only molybdenum the carbide phase contained nearly all the Mo; the sum of the Mo content of the carbide phase and of the solid solution even exceeded the average Mo concentration of the steel because of migration toward the grain boundary. The presence of Cr and Ni in the steel reduced this enrichment effect in the fracture surface. (TTT)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-14-019466
- OSTI ID:
- 4175818
- Journal Information:
- Zavodskaya Lab., Journal Name: Zavodskaya Lab. Vol. Vol: 26
- Country of Publication:
- Country unknown/Code not available
- Language:
- Russian
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Related Subjects
ANODES
CARBIDES
CATHODES
CHROMIUM
CHROMIUM ALLOYS
CRACKS
ELECTRIC CONDUCTIVITY
EVAPORATION
FAILURES
GRAIN BOUNDARIES
HYDROCHLORIC ACID
HYDROGEN PEROXIDES
LAYERS
MELTING
METALS, CERAMICS, AND OTHER MATERIALS
MIXING
MOLYBDENUM
MOLYBDENUM ALLOYS
MOLYBDENUM CARBIDES
NICKEL
NICKEL ALLOYS
PLATINUM
POTASSIUM SULFATES
QUALITATIVE ANALYSIS
QUANTITY RATIO
RESIDUES
SOLID SOLUTIONS
SOLUTIONS
STEELS
SURFACES
THICKNESS
WIRES