Effects of carbonitride-forming microadditions on the cold brittleness of quenched-and-tempered steel

Effects of titanium, boron, and nitrogen microadditions to 40 KhN steel on the resistance to brittle failure and properties sensitive to local microstresses in the metal, i.e., on the internal friction and stress relaxation were investigated. The microalloyed steel was found to exhibit greater resistance to brittle fracture, which is a result of the decreasing tendency to formation of local microstresses in the metal under load.