MICRO-ALLOYING ADDITIVES FOR STEEL 4KhV2S.

A study has been made of the possibility of improving the properties of steel 4KhV2S by making small additions of B (0. 01, 0. 03 and 0. 05 percent), Ce (0. 05, 0. 10 and 0. 20 percent) and V (0. 10, 0. 20 and 0. 30 percent). The most effective treatments for the ingots were 0. 10-0. 20 percent ferrocerium and 0. 2-0. 3 percent V. Cerium raised the ductility of the steel by 70-100 percent and its tensile strength by 11 percent over the values for the untreated steel. The biggest increment in ductility (2- to 3-fold) was achieved by alloying the steel 4KhV2S with vanadium, which also increased its tensile strength by 7-10 percent. This can be attributed to the extreme refinement of the dendrite structure and the formation of smaller carbide particles. The addition of 0. 01-0. 05 percent B gave some structural refinement and produced a shallower columnar zone, but the mechanical properties of the steel were not improved above the normal very low levels.