Which one of the following elements is alloyed with iron to produce steel which can resist high temperatures and also have high hardness and abrasion resistance?

1. The question asks which element is alloyed with iron to produce steel that resists high temperatures and has high hardness and abrasion resistance. 2. Aluminium is used in some alloys but not typically for high-temperature, high-hardness steel applications. 3. Chromium is added to iron to make stainless steel, improving corrosion resistance and hardness. High-chromium steels can also have good high-temperature strength. 4. Nickel improves toughness, corrosion resistance, and performance at both high and low temperatures, often used with chromium in stainless steels. 5. Tungsten is added to iron (often along with chromium and vanadium) to create high-speed steels (HSS). Tungsten significantly increases hardness, abrasion resistance, and crucially, 'red hardness' - the ability to retain hardness at high temperatures (like those encountered in cutting tools). This combination of properties best matches the description.