抄録
Direct observations were carried out to study the morphology of vanadium carbide V4C3 and the crystallographic orientation relationship between the carbide and matrix in an iron-5% vanadium alloy, containing a small amount of carbon, which was aged at 600°C for various times after quenching from 1200°C into 10% iced brine. The results are as follows: (1) The as-quenched structure consists of simple ferrite and contains a few irregularly distributed dislocations only. Dislocation loops, helical dislocations and precipitates are not present. (2) Large numbers of square or rectangular-shaped thin platelets appear, accompanied by a slight increase in hardness on aging at 600°C. (3) These very thin platelets are identified as vanadium carbide V4C3 containing a small amount of nitrogen by chemical analysis and X-ray diffraction of extracted residues. (4) A definite crystallographic orientation relationship between vanadium carbide and ferrite matrix was determined by analysing a number of electron diffraction patterns as shown in the following: (100)_V4C3 \varparallel(100)_α-Fe, [010]_V4C3 \varparallel[011]_α-Fe, [001]_V4C3 \varparallel[0 \bar11]_α-Fe.
