ISSN:
0142-2421
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
Investigations have been performed on the effects of the alloying elements Ti, Nb, Mo and V on the grain boundary segregation of phosphorous in iron and steels. The methods are AES analysis of grain boundaries on intergranular fracture faces and field-ion microscopy and mass spectrometry (atomprobe). The elements Ti and Nb show strong interaction with P, keeping P in the grain and decreasing its grain boundary segregation. In the alloys and steels containing carbon, Ti and Nb react under formation of carbides, therefore with increasing C content the grain boundary segregation of P increases. For stoichiometric ratio Ti/C and Nb/C the segregation reaches a maximum; at higher carbon contents C displaces P from the grain boundaries. Some interfacial segregation of P is observed at or near the ferrite/carbide interface in the case of TiC, leading to a decrease of grain boundary segregation. The same effect applies for Mo2C but not for NbC. In contrast to Ti and Nb there is no direct interaction of Mo and P, which is also in contradiction to previous assumptions on the role of molybdenum in the temper embrittlement of low alloy steels.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/sia.740100405
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