Influence of phosphorus on the properties of 45Kh10G14Yu2 steel

1. Phosphorus increases the tendency of 45Kh10G14Yu2 steel to austenite grain growth at 1200–1250°C. 2. Phosphorus concentrations from 0.009 to 0.043% do not affect the ductility of the steel during high-temperature plastic deformation. 3. Phosphorus increases the strength of the steel at room temperature and reduces the ductility somewhat; the hardening influence of phosphorus is retained at 630 and 700°C. 4. As the phosphorus content is increased from 0.009 to 0.043% the time before fracture increases 300% in long-term strength tests (at δ=18 kg/mm2, 630°C) and the steady creep rate decreases. 5. The ductility of the quenched steel decreases slightly as the phosphorus content is increased. Age-hardening at 630°C leads to reduction of the impact strength. This decrease of the impact strength during age-hardening is caused by the precipitation of carbides and does not depend on the phosphorus content. 6. The mechanical properties and plasticity of the steel with 0.043% P are not inferior to those of the steel with lower phosphorus concentrations at room or elevated temperatures.