Chromium and molybdenum are key elements in the composition of P11 steel. Chromium enhances high-temperature strength, improves oxidation resistance, and boosts the tensile, yield, and hardness properties at room temperature. Molybdenum, on the other hand, contributes to increased strength, elastic limit, wear resistance, and impact toughness. It also improves hardenability, resists softening, and limits grain growth. Molybdenum plays a crucial role in making chromium steel less prone to embrittlement and is particularly effective in enhancing high-temperature creep resistance. Additionally, molybdenum enhances the steel's corrosion resistance and prevents pitting.