Fluctuations in Chemical Composition of M₇C₃ Carbides in the Soft Annealed Nc11lv/D2 Steel

Abstract

The paper presents the study results on chemical composition of the coarse primary M 7 C 3 carbides occurring in the soft annealed NC11LV/D2 tool steel consisting of: 1.53% C; 11.65% Cr; 0.01% W; 0.81% Mo; 0.068% V; (balance iron plus admixtures), used for cold operation. The microanalyzer of type SEMPROBE Su-30, French made by CAMECA Co., equipped with two WDS X-ray spectrometers and an EDS VOYAGER 3 100, NORAN Instruments Co., made in USA. It was found that out of the three alloying elements occurring in the big carbides of the annealed NC11LV/D2 steel, i.e. Cr, Mo, and V, the chromium appears to be the most uniformly distributed. The big carbides vary concerning C, Cr, Mo, V; the greatest differentiation degree of the contents of Mo and Cr, and the least -of vanadium. The average chemical composition of the big/coarse carbides is as follows: C = 9.42±1.28%; Cr = 44.17±2.95%; Mo = 4.48±3.52%; V = 4.53±0.31%; balance Fe.

The Influence of Austenitizing Temperature Level on Microstructure Development in Chromium Ledeburitic Tool Steel

“…As abovementioned, the carbides of K1 type have greater size (2.5-22 μm), and are situated on the grain boundaries. In many cases the K1 have irregular or angular shape, very similar to rod and rectangles [3,6,8,10,13]. Besides that, the same chemical composition was also identified for smaller-sized particles which have mostly quasi-globular shape [13].…”

“…In many cases the K1 have irregular or angular shape, very similar to rod and rectangles [3,6,8,10,13]. Besides that, the same chemical composition was also identified for smaller-sized particles which have mostly quasi-globular shape [13]. The largest particles belong to the eutectic carbides.…”