The strength of chromium carbide hard alloys

Summary

• 1. Chromium carbide alloys cemented with nickel are characterized by the presence of a continuous carbide skeleton at nickel contents of up to 30%.

• 2. With increasing temperature, the strength of chromium carbide alloys with a skeletal structure passes through a maximum, which may be ascribed to two factors: a) increased strength of the carbide skeleton at higher temperatures, resulting from reduced effectiveness of structural microdefects as stress raisers; b) reduced strength of the alloy as a whole, resulting from a marked decrease in the strength of the metallic phase beyond the critical temperature of physical strength loss.

• 3. Results of bending strength tests have demonstrated that the scatter of strength values, which is due to the high brittleness and structural imperfection of chromium carbide alloys, decreases significantly with increasing test temperature. This phenomenon is due to stress relaxation in stress microraisers and the healing up of structural microdefects, which leads to reduced brittleness and a partial realization of the physical strength of the carbide skeleton.